1991 Mercury Grand Marquis Spark Plugs

Keep Your 1991 Mercury Grand Marquis in Top Shape with Quality Spark Plugs

Whether you’re repairing or upgrading your Spark Plug, using high-quality parts is key to keeping your 1991 Mercury Grand Marquis looking sharp and performing at its best. At Advance Auto Parts we carry a wide selection of dependable options, including Spark Plugs and Spark Plug Wire Set Cut To Fits. Whether you’re replacing a damaged part or enhancing your truck’s style and protection, you’ll find exactly what you need to get the job done right.

Top-Rated Spark Plugs from Trusted Brands

Looking for a reliable Spark Plug? We’ve got you covered with options from brands you know and trust like NGK, DENSO, and Autolite. For example, NGK Spark Plugs start at just $5.99 with an average 4.8 star rating. DENSO and Autolite offer similar pricing and quality, backed by strong customer feedback. With over 587 reviews and a solid 5 star average, you can shop with confidence knowing other Mercury Grand Marquis owners approve.

Competitive Prices and Extensive Inventory

The average price for a 1991 Mercury Grand Marquis Spark Plug at Advance Auto Parts is around $19.13, with a range that starts at $2.49 and goes up to $99.99. With 18 options in stock from 7 trusted brands, finding the right fit is easy. Popular picks like Iridium TT Spark Plug: Ultimate Endurance and Power, 0.4mm Iridium Tip, IT16TT, Iridium Power Spark Plug: Maximum Spark Energy, 0.4mm Iridium Tip, IT16, and High-Performance Shorty Spark Plug: Enhanced Clearance & Heat Dissipation start at just $9.99 and offer a great balance of form and function.

Explore Related Parts

While you’re upgrading or replacing your Spark Plug, don’t forget to check out other key components like Ignition Boots and Ignition Coils and Boots. At Advance Auto Parts, we’re here to help you keep your 1991 Mercury Grand Marquis in peak condition, inside and out.

Essential 1991 Mercury Grand Marquis Spark Plugs

Motorcraft – Platinum Spark Plug (AGSF32FM): Enhanced Durability & Reliability (Part No.SP-432)

Platinum Spark Plug (AGSF32FM): Enhanced Durability & Reliability

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$6.99
Platinum Spark Plug (AGSF32FM) offers enhanced durability and reliability, making it the ideal choice for maintaining peak performance in Ford, Lincoln, and Mercury vehicles. Engineered to meet strict Ford standards, these spark plugs are crafted with platinum center and ground electrode tips for superior resistance to oxidation and arc erosion. Designed for exact fitment, they help eliminate misfires, reduce fuel consumption, and optimize emissions, ensuring smooth and efficient engine operation. The multi-rib insulator provides added protection against misfires, while service intervals of up to 100,000 miles deliver long-lasting value. Backed by Motorcraft’s Service Parts Warranty, these spark plugs are built with high-quality materials to provide reliable performance across a wide range of domestic and import applications. Whether you’re replacing original equipment or upgrading, Motorcraft Spark Plugs are the trusted solution to prevent false check engine lights and maintain your vehicle’s reliability.

Product Features:
  • Motorcraft spark plugs are matched to specific engines to provide enhanced durability, eliminate misfires, reduce fuel consumption and optimize emissions.
  • Backed by Motorcraft’s Service Parts Warranty
  • Exact fit for Ford, Lincoln and Mercury vehicles
  • Resistant to oxidation and arc erosion.
  • Multi-rib insulator protects against misfire.
  • Service intervals of up to 100,000 miles.
  • Motorcraft Spark Plugs are designed with high quality materials to provide reliable performance for almost any application.
  • Motorcraft Spark Plugs are what was in the vehicle when it was manufactured
  • Motorcraft ignition components help prevent false check engine lights.
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Motorcraft – Spark Plug: Quick Starts & Enhanced Fuel Economy (Part No.F1000567114MTR)

Spark Plug: Quick Starts & Enhanced Fuel Economy

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$4.97
Motorcraft Original Equipment spark plugs are the trusted choice for maintaining your vehicle’s peak performance. Designed, engineered, and recommended by Ford Motor Company, these spark plugs are the same high-quality parts installed when your engine first rolled off the assembly line. Featuring a 100,000-mile service interval, they deliver long-lasting reliability, reducing the need for frequent replacements. The iridium-enhanced center electrode ensures exceptional durability and wear resistance, while the .6mm finewire design enhances ignitability for efficient combustion. Built for overall durability, these spark plugs resist gap erosion, ensuring consistent performance over time. Perfectly tailored for Ford vehicles, they provide unmatched compatibility and value, making them an essential choice for maintaining your engine’s health and efficiency.

Product Features:
  • Same part installed when the engine rolled off the assembly line
  • 100,000-mile service interval
  • Iridium-enhanced center electrode for improved durability and wear resistance
  • .6mm finewire design improves ignitability
  • Designed for overall durability with virtually no gap erosion
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Autolite – Double Platinum Spark Plug: Enhanced Durability & Performance (Part No.APP104)

Double Platinum Spark Plug: Enhanced Durability & Performance

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$6.99
Double Platinum Spark Plug: Enhanced Durability & Performance is engineered for exceptional reliability and efficiency, making it a top choice for distributor-less ignition system (DIS) engines. Featuring a platinum-to-platinum design, it minimizes gap erosion and reduces misfires, ensuring consistent performance and extended service life. The yttrium-enhanced ground electrode offers superior heat transfer, allowing the spark plug to withstand high temperatures and pressures for greater durability. Its high alumina ceramic insulator optimizes thermal conductivity and dielectric strength, while the multi-rib insulator prevents flash-over for added safety and reliability. With a mid-projection center electrode and tapered seat type, this performance-grade spark plug delivers precision and compatibility. Both the center and ground electrode tips are crafted from platinum, ensuring long-lasting efficiency and superior ignition performance. Designed to outperform copper and standard platinum plugs, this spark plug is a durable and high-value solution for maintaining peak engine performance.

Product Features:
  • Engineered with a platinum-to-platinum design that prevents gap erosion, extending the life of the spark plug.
  • The yttrium-Enhanced Ground Electrode delivers superior heat transfer that delivers more durability under high temps and pressure for greater life.
  • Its high alumina ceramic insulator provides optimum thermal conductivity and dielectric strength.
  • The multi-rib insulator prevents flash-over.
  • Designed with a mid-projection center electrode and tapered seat type for enhanced precision and compatibility with distributor-less ignition system (DIS) engines.
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NGK – Laser Iridium Spark Plug (ITR5H13): Fine Wire Tip for Precision (Part No.97287)

Laser Iridium Spark Plug (ITR5H13): Fine Wire Tip for Precision

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$23.99
NGK Laser Iridium spark plugs offer the best combination of performance and longevity. Engineered specifically for OE applications, Laser Iridium spark plugs are tested to the highest standards to ensure quality and durability. Iridium tipped center electrode provides durability six times harder than platinum. NGKs high grade pure alumina ceramic and 98 percent pure copper core prevents the spark plug from overheating while providing reliable starts. Most Laser Iridium spark plugs feature a platinum pad on the ground electrode for even wear in distributorless ignition systems.

Product Features:
  • ACTUAL OE or EQUIVALENT DESIGN: OEM quality construction fine wire iridium alloy center electrode provides consistent performance
  • IRIDIUM ALLOY CENTER ELECTRODE: Iridium’s density (6x that of platinum) and extremely high melting point is perfect for modern high efficiency engines
  • PLATINUM TIP GROUND ELECTRODE: Unless OE specified, platinum protection at the ground electrode provides excellent ignitability and service life
  • SOLID COPPER CORE: 98% pure copper core offers superior heat dissipation, conductivity and ultra wide heat ranges
  • TRIVALENT METAL PLATING: Delivers superior anti-corrosion and anti-seizing properties, ensuring ease of installation and removal
  • RECOMMENDED USAGE: Best for vehicles with OE fine wire iridium alloy plugs
  • Superior Durability: The iridium-tipped center electrode is six times harder than platinum, ensuring long-lasting performance.
  • OE Application Specific: Engineered specifically for Original Equipment (OE) applications, ensuring a perfect fit and optimal performance.
  • Even Wear: Features a platinum pad on the ground electrode for even wear, particularly beneficial in distributorless ignition systems.
  • Fine Wire Tip Design: The fine wire tip design of the ITR5H13 model enhances ignition efficiency and performance.
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DENSO – Iridium Power Spark Plug: Maximum Spark Energy, 0.4mm Iridium Tip, ITF20 (Part No.5331)

Iridium Power Spark Plug: Maximum Spark Energy, 0.4mm Iridium Tip, ITF20

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$6.99
The Iridium Power Spark Plug features the world’s smallest Iridium Center Electrode at just 0.4mm, delivering enhanced spark energy for maximum combustion efficiency. Engineered with a patented 360-degree laser welding assembly process, it ensures unmatched durability and precision. The U-groove and taper-cut ground electrode design optimizes flame propagation, improving overall engine performance. Built to withstand extreme temperatures exceeding 4000 degrees Fahrenheit, this spark plug is burnished with nickel plating for exceptional high-temperature endurance and superior corrosion resistance. Its iridium tip material guarantees long-lasting reliability, while the tapered seat type ensures a secure fit. With a wide range of part numbers available, it caters to thousands of applications, including classic and collector cars. Choose this spark plug for unparalleled performance and durability.

Product Features:
  • World’s smallest Iridium Center Electrode (0.4mm) for improved spark for maximum combustion
  • Patented 360-degree laser welding assembly process
  • U-groove and taper cut ground electrode to maximize flame propagation.
  • Withstands temperatures greater than 4000 degree Fahrenheit
  • Burnished nickel plating for high temperature endurance and superior corrosion resistance
  • Wide range of part numbers for thousands of applications, including classic and collector cars
  • Iridium Power
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Autolite Iridium – Iridium XP Fine wire Spark Plug: Improved Durability, More Focused Ignition (Part No.XP25)

Iridium XP Fine wire Spark Plug: Improved Durability, More Focused Ignition

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$10.99
Autolite has over 100 years of engineering experience and has sold over 11 billion plugs. Designed and engineered in the USA, the Autolite Iridium XP spark plugs feature an iridium-enhanced 0.6mm finewire design and patented platinum sidewire technology to provide better overall durability and a more focused ignition for enhanced ignitability and performance. Features double Iridium-enhanced alloy technology center electrode for improved durability and wear resistance.

Product Features:
  • 0.6 mm finewire design improves ignitability
  • Patented V-trimmed platinum sidewire technology resists wear
  • OE equivalent design is engineered for every engine
  • Designed for better overall durability with virtually no gap erosion
  • Double Iridium-enhanced alloy technology center electrode ensures superior wear resistance for extended performance longevity.
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Autolite – Copper Resistor Spark Plug: Quick Starts & Enhanced Durability (Part No.25)

Copper Resistor Spark Plug: Quick Starts & Enhanced Durability

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$4.29
Autolite Copper spark plugs are designed to provide reliable performance and durability, making them an excellent choice for maintaining your vehicle’s efficiency. Featuring a copper core center electrode, these spark plugs excel in thermal control and resist fouling, ensuring consistent operation. The high nickel alloy center and ground electrodes are engineered for extended life, while the nickel-plated shell offers superior corrosion resistance for long-lasting durability. The high alumina multi-rib ceramic insulator enhances thermal conductivity and insulation, contributing to increased strength and reliability. With a mid-projection standard center electrode design and a tapered seat type, these spark plugs are built for optimal compatibility and performance. Engineered to improve fuel economy, they help reduce fuel costs without compromising on power. Additionally, their advanced design ensures smoother acceleration, delivering a more responsive and enjoyable driving experience. Ideal for regular-grade applications, these spark plugs combine value, efficiency, and durability to meet your vehicle’s performance needs.

Product Features:
  • The copper core center electrode aids in thermal control and improves resistance to fouling.
  • Its specially engineered high nickel alloy center and ground electrode provides extended life.
  • The high alumina multi-rib ceramic insulator provides thermal conductivity and superior insulation for increased strength.
  • Designed with a nickel-plated shell that is corrosion resistant to provide increased durability for extended periods.
  • Good Fuel Economy: Engineered to optimize fuel efficiency, these spark plugs help you save on fuel costs while maintaining excellent performance.
  • Smooth Acceleration: Experience smoother acceleration with Autolite’s advanced copper spark plug design, providing a more responsive driving experience.
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Champion – Double Platinum Power Spark Plug (RS12PYPB5): Enhanced Durability & Performance (Part No.7963)

Double Platinum Power Spark Plug (RS12PYPB5): Enhanced Durability & Performance

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$6.99
Champion Double Platinum Power spark plugs are engineered to deliver exceptional performance and durability for your vehicle. Featuring a fine-wire platinum center electrode and a platinum pad ground electrode, these spark plugs ensure greater wear resistance and sharper spark focus for reliable ignition. The innovative Heat-Active alloy allows the electrodes to maintain optimal operating temperatures under all engine loads, enhancing overall efficiency. With a V-trimmed ground electrode design, these plugs promote precise spark delivery, improving ignitability and engine performance. Designed as a standard replacement, they are built to provide maximum life and consistent performance, making them a dependable choice for maintaining your vehicle’s peak operation. Equipped with a resistor and a tapered seat type, these spark plugs are a perfect blend of advanced technology and practicality, ensuring stable performance and long-lasting reliability.

Product Features:
  • Double Platinum Power – Premium Spark Plug. More Powerful Performance.
  • Platinum center and ground electrode for greater wear resistance
  • Maintains stable operating temperature under all engine loads
  • Fine-wire center electrode for greater ignitability
  • V-trimmed ground electrode promotes sharper spark focus
  • Heat-Active alloy allows electrodes to reach optimal temperature
  • Platinum Center Electrode Tip: Guarantees maximum life and exceptional performance.
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Autolite – Platinum Spark Plug: Enhanced Durability & Performance (Part No.AP5145)

Platinum Spark Plug: Enhanced Durability & Performance

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$4.99
Autolite Platinum spark plugs are crafted for superior performance and durability, making them ideal for older engine applications. Featuring a platinum center electrode firing tip, these spark plugs ensure quicker firing, smoother starts, better acceleration, and improved fuel efficiency. The platinum firing tip prevents gap erosion, extending the service life, while the high alumina ceramic insulator enhances thermal conductivity and insulation for added strength. Designed with a long projection standard center electrode and a nickel-plated shell, these spark plugs resist corrosion and deliver extended durability. The multi-rib insulator prevents flash-over, ensuring reliable operation, and the tapered seat type offers a secure fit. With a performance-grade design and nickel ground electrode tip material, these spark plugs are built to meet the demands of high-performance engines while maintaining consistent reliability. Whether you’re seeking enhanced efficiency or long-lasting durability, these spark plugs are a dependable choice for your vehicle.

Product Features:
  • Engineered with a platinum firing tip that prevents gap erosion for longer service life.
  • Its high alumina ceramic insulator provides thermal conductivity and superior insulation for increased strength.
  • The multi-rib insulator prevents flash-over.
  • Designed with a nickel-plated shell that is corrosion resistant to provide increased durability for extended life.
  • Built with a tapered seat type for a secure and precise fit, ensuring reliable performance and compatibility with high-performance engines.
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Autolite – Copper Resistor Spark Plug: Smooth Acceleration & Enhanced Durability (Part No.764)

Copper Resistor Spark Plug: Smooth Acceleration & Enhanced Durability

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$2.99
Autolite Copper spark plugs are crafted to deliver reliable performance and meet your vehicle’s demands with precision. Featuring a copper core center electrode, these spark plugs excel in thermal control and resist fouling, ensuring consistent operation. The high nickel alloy center and ground electrodes are engineered for extended life, while the nickel-plated shell offers superior corrosion resistance for long-lasting durability. With a high alumina multi-rib ceramic insulator, these spark plugs provide excellent thermal conductivity and insulation, enhancing strength and reliability. Designed for smooth acceleration, they elevate your driving experience while promoting good fuel economy for greater efficiency. The tapered seat type ensures an optimal fit and performance, while the mid-projection standard center electrode design and nickel tip materials further enhance functionality. Perfect for regular-grade applications, these spark plugs combine durability, efficiency, and smooth operation to keep your vehicle running at its best.

Product Features:
  • The copper core center electrode aids in thermal control and improves resistance to fouling.
  • Its specially engineered high nickel alloy center and ground electrode provides extended life.
  • The high alumina multi-rib ceramic insulator provides thermal conductivity and superior insulation for increased strength.
  • Designed with a nickel-plated shell that is corrosion resistant to provide increased durability for extended periods.
  • Smooth Acceleration: Designed to provide smooth acceleration, enhancing your driving experience.
  • Good Fuel Economy: These spark plugs help in maintaining good fuel economy, making your vehicle more efficient.
  • Tapered Seat Type: Features a tapered seat type for optimal fit and performance.
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NGK – V-Power Nickel Spark Plug (TR55-1): Enhanced Ignitability & Performance (Part No.2683)

V-Power Nickel Spark Plug (TR55-1): Enhanced Ignitability & Performance

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$5.99
NGK V-Power spark plugs offer reliable performance and improved ignitability over standard nickel plugs. Engineered specifically for OE applications, the special V-cut nickel alloy center electrode and concave ground electrode of NGK’s V-Power spark plug increases ignitability providing quicker starts and smoother idle. NGK’s legendary high grade alumina silicate ceramic creates a stronger insulator for optimal dielectric performance. Trivalent metal plating ensures superior anti-corrosion and anti-seizing properties.

Product Features:
  • ACTUAL OE or EQUIVALENT DESIGN: OEM quality construction nickel alloy center electrode with V-groove provides consistent performance
  • RECOMMENDED USAGE: Best for vehicles with OE nickel alloy plugs, not recommended on vehicles with factory precious metal plugs
  • NGK’s OE CERAMIC TECHNOLOGY: High grade alumina silicate ceramic creates a stronger insulator for optimal dielectric performance
  • SOLID COPPER CORE: 98% pure copper core offers superior heat dissipation, conductivity and ultra wide heat ranges
  • COLD-ROLLED THREADS: Prevents cross-threading and damage to cylinder heads
  • TRIVALENT METAL PLATING: Delivers superior anti-corrosion and anti-seizing properties, ensuring ease of installation and removal
  • Enhanced Ignitability: The V-cut nickel alloy center electrode and concave ground electrode design of NGK V-Power spark plugs provide quicker starts and smoother idle.
  • OE Application Specific: Engineered specifically for Original Equipment (OE) applications, ensuring compatibility and reliable performance.
  • V-Groove Tip Design: The unique V-Groove tip design of the TR55-1 model enhances ignitability and overall engine performance.
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Autolite – Copper Resistor Spark Plug: Quick Starts & Enhanced Durability (Part No.26)

Copper Resistor Spark Plug: Quick Starts & Enhanced Durability

from

$4.29
Autolite Copper spark plugs are designed to provide reliable performance and durability, making them an excellent choice for maintaining your vehicle’s efficiency. Featuring a copper core center electrode, these spark plugs excel in thermal control and resist fouling, ensuring consistent operation. The high nickel alloy center and ground electrodes are engineered for extended life, while the mid-projection design optimizes spark delivery. A high alumina multi-rib ceramic insulator enhances thermal conductivity and insulation, contributing to superior strength and reliability. The nickel-plated shell offers exceptional corrosion resistance, ensuring long-lasting durability even in demanding conditions. With a tapered seat type and integrated resistor, these spark plugs are built to meet performance expectations, delivering quick starts and the power your vehicle needs.

Product Features:
  • The copper core center electrode aids in thermal control and improves resistance to fouling.
  • Its specially engineered high nickel alloy center and ground electrode provides extended life.
  • The high alumina multi-rib ceramic insulator provides thermal conductivity and superior insulation for increased strength.
  • Designed with a nickel-plated shell that is corrosion resistant to provide increased durability for extended periods.
  • The integrated resistor minimizes electrical interference, ensuring smoother engine performance and reliable ignition.
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Autolite – Double Platinum Spark Plug: Enhanced Durability & Performance (Part No.APP25)

Double Platinum Spark Plug: Enhanced Durability & Performance

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$6.99
The Double Platinum Spark Plug is engineered for exceptional durability and performance, making it a top choice for distributor-less ignition system (DIS) engines. Featuring a platinum-to-platinum design, it minimizes gap erosion and reduces misfires, ensuring a longer service life compared to copper and standard platinum plugs. Its yttrium-enhanced ground electrode delivers superior heat transfer, allowing it to withstand high temperatures and pressures for extended durability. The high alumina ceramic insulator optimizes thermal conductivity and dielectric strength, while the multi-rib insulator prevents flash-over for reliable operation. With a mid-projection center electrode and tapered seat type, this performance-grade spark plug is designed to deliver consistent ignition and efficiency. Both the center and ground electrode tips are crafted from platinum, ensuring robust functionality and reliability. Ideal for drivers seeking enhanced engine performance and longevity, this spark plug is built to meet the demands of modern engines.

Product Features:
  • Engineered with a platinum-to-platinum design that prevents gap erosion, extending the life of the spark plug.
  • The yttrium-Enhanced Ground Electrode delivers superior heat transfer that delivers more durability under high temps and pressure for greater life.
  • Its high alumina ceramic insulator provides optimum thermal conductivity and dielectric strength.
  • The multi-rib insulator prevents flash-over.
  • Designed with a mid-projection center electrode and tapered seat type to ensure consistent ignition and improved engine efficiency.
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NGK – V-Power Nickel Spark Plug (UR45): Reliable Performance & Ignitability (Part No.6945)

V-Power Nickel Spark Plug (UR45): Reliable Performance & Ignitability

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$6.99
NGK V-Power spark plugs offer reliable performance and improved ignitability over standard nickel plugs. Engineered specifically for OE applications, the special V-cut nickel alloy center electrode and concave ground electrode of NGK’s V-Power spark plug increases ignitability providing quicker starts and smoother idle. NGK’s legendary high grade alumina silicate ceramic creates a stronger insulator for optimal dielectric performance. Trivalent metal plating ensures superior anti-corrosion and anti-seizing properties.

Product Features:
  • ACTUAL OE or EQUIVALENT DESIGN: OEM quality construction nickel alloy center electrode with V-groove provides consistent performance
  • RECOMMENDED USAGE: Best for vehicles with OE nickel alloy plugs, not recommended on vehicles with factory precious metal plugs
  • NGK’s OE CERAMIC TECHNOLOGY: High grade alumina silicate ceramic creates a stronger insulator for optimal dielectric performance
  • SOLID COPPER CORE: 98% pure copper core offers superior heat dissipation, conductivity and ultra wide heat ranges
  • COLD-ROLLED THREADS: Prevents cross-threading and damage to cylinder heads
  • TRIVALENT METAL PLATING: Delivers superior anti-corrosion and anti-seizing properties, ensuring ease of installation and removal
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Accel – 8Mm Super Stock Spiral Uni Bk (Part No.5040K)

8Mm Super Stock Spiral Uni Bk

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$99.99
The traditional ACCEL combination of yellow wire and red spark plug boots has been added to these SuperStock Spiral Core 5000 Series wire sets, which feature color-matched wire and spark plug boots in blue, black, and red. With only 500 ohms/ft. of resistance, more ignition energy can reach the spark plug, producing a longer-lasting, hotter spark flame kernel. The results is higher performance through improved efficiency, quicker throttle response, and reduced emissions. This 8mm wire’s double silicone construction is rated to 550 degrees F. The high-gloss wire jacket resists moisture, chemicals, and heat extremes for longer life and great looks. The fiberglass braid adds greater pull strength and terminal retention, while the stainless steel spark plug terminals provide excellent long life, electrical conductivity, and corrosion resistance. Both universal and custom-fit applications are available for early and late model cars and trucks.

Product Features:
  • 500 Ohms/ft Of Resistance
  • 550 F Rated Silicone Jacket
  • Stainless Steel Plug Terminals
  • High RFI Suppression For Street And Strip Use
  • Universal And Import Coverage
  • High-strength Fiberglass Braid Construction
  • Pre And Post HEI Vehicles
  • 8mm High Gloss Silicone Jacket
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Accel – 8Mm Super Stock Graphite Uni (Part No.4040B)

8Mm Super Stock Graphite Uni

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$71.99
ACCEL’s SuperStock 4000 series spark plug wire sets are designed to upgrade an OE ignition system for high-spark delivery levels for street driven applications. The 450 degree F rated silicone jacket is extruded over a tightly woven, rugged fiberglass braid. The braid is applied over high dielectric strength EPDM (Ethylene Propylene Diene Monomer) inner insulation for ignition wire performance that exceeds SAE specifications.

Product Features:
  • 7mm And 8mm High Gloss Silicone Jacket
  • 450 F Rated Silicone Jacket
  • Stainless Steel Plug Terminals
  • RFI Suppression For Street Driven Applications
  • Custom-fit Universal And Import Coverage
  • High-strength Fiberglass Braid Construction
  • Pre And Post HEI Vehicles
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Most Popular Spark Plugs for 1991 Mercury Grand Marquis

Enhance your 1991 Mercury Grand Marquis with one of the 16 Spark Plugs we have in stock, starting at just $2.49.

Accel – High-Performance Shorty Spark Plug: Enhanced Clearance & Heat Dissipation (Part No.8199)

High-Performance Shorty Spark Plug: Enhanced Clearance & Heat Dissipation

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$57.99
ACCEL’s patented race proven spark plugs in a Shorty configuration. The overall length has been reduced 3/16 in to 3/8 in (depending on the specific spark plug) to gain critical air gap between the spark plug boot and the exhaust manifold or header tube. This helps eliminate burning the spark plug boot or dimpling the header tube. The shorter spark plug length also can make it easier to install an remove the spark plugs in certain applications where there is not a lot of room to fit a socket or move a wrench around. ACCEL Shorty Spark Plugs are made with a Copper core which is a better conductor than Platinum and Iridium. They deliver a stronger spark especially in high performance applications where high combustion pressures are present. Copper is much better at dissipating heat than other materials which lessens the chance of a misfire. ACCEL Shorty Spark Plugs are capable allowing you to open the gap exposing a larger flame kernel or close it if needed for high boost applications. All ACCEL Shorty Spark Plugs have machine rolled threads allowing for a more precise thread engagement and torque retention.

Product Features:
  • Shorty Spark Plugs For Tubular Exhaust Headers
  • Eliminates Dimpling Headers For Added Clearance
  • Improves Spark Plug Access To Fit Socket Or Wrench
  • Shorter Overall Plug Length Vs. OE Style Plug
  • Copper Core Center Electrode
  • Projected Tip
  • Helps Eliminate Burned Spark Plug Boots
  • Shorty Header Spark Plug
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Autolite – Copper Resistor Spark Plug: Quick Starts & Reliable Performance (Part No.2545)

Copper Resistor Spark Plug: Quick Starts & Reliable Performance

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$3.99
Autolite Copper spark plugs are designed to deliver reliable performance, ensuring quick starts and the power your vehicle demands. Featuring a copper core center electrode, these plugs excel in thermal control and resist fouling, while the high nickel alloy center and ground electrodes provide extended durability. The high alumina multi-rib ceramic insulator enhances thermal conductivity and insulation, offering superior strength. With a corrosion-resistant nickel-plated shell, these spark plugs are built to last. Their tapered seat design ensures a secure fit, while the long projection center electrode optimizes performance. Engineered to meet or exceed Original Equipment Service (OES) Standards, they guarantee dependable operation. Additionally, these spark plugs are designed to improve fuel economy and deliver smoother, more responsive acceleration, making them a valuable upgrade for your vehicle.

Product Features:
  • The copper core center electrode aids in thermal control and improves resistance to fouling.
  • Its specially engineered high nickel alloy center and ground electrode provides extended life.
  • The high alumina multi-rib ceramic insulator provides thermal conductivity and superior insulation for increased strength.
  • Designed with a nickel-plated shell that is corrosion resistant to provide increased durability for extended periods.
  • Good Fuel Economy: Designed to optimize fuel consumption, these spark plugs help you achieve better mileage.
  • Smooth Acceleration: Experience smoother and more responsive acceleration with Autolite Copper Core spark plugs.
  • OES Design Compliance: These spark plugs meet or exceed Original Equipment Service (OES) design requirements, ensuring reliable performance.
  • Tapered Seat Type: Featuring a tapered seat type, these spark plugs provide a secure fit and optimal performance.
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NGK – G-Power Platinum Spark Plug (TR55-1GP): Enhanced Durability & Efficiency (Part No.7159)

G-Power Platinum Spark Plug (TR55-1GP): Enhanced Durability & Efficiency

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$8.49
NGK G-Power Platinum spark plugs are the best single platinum spark plugs at an economical price. G-Power plugs feature a fine wire platinum center electrode and a trapezoidal cut ground electrode that offers increased durability, improved fuel efficiency, lower emissions, faster starts and quicker acceleration over conventional nickel spark plugs. An excellent upgrade for vehicles which used nickel alloy spark plugs originally. For better performance consider upgrading to a NGK Iridium IX plug. For even greater performance consider upgrading to a NGK RUTHENIUM HX plug.

Product Features:
  • SINGLE PLATINUM TIP: Fine wire 0.6 millimeter platinum tip center electrode ensures improved durability and a consistently stable spark
  • PLATINUM ALLOY: G-Power platinum provides exceptional value with increased performance and longer service intervals than factory nickel plugs
  • TRAPEZOIDAL CUT GROUND ELECTRODE: Reduces quenching design produces improved ignitability and performance
  • SOLID COPPER CORE: 98% pure copper core offers superior heat dissipation, conductivity and ultra wide heat ranges
  • COLD-ROLLED THREADS: Prevents cross-threading and damage to cylinder heads
  • RECOMMENDED USAGE: Lower cost alternative to double precious metal spark plugs or as an upgrade to OE nickel alloy spark plugs
  • Enhanced Performance: Provides better performance over conventional nickel spark plugs, making it a smart choice for vehicle maintenance.
  • Tapered Seat Type: Designed with a tapered seat type for a secure fit and optimal performance.
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NGK – Iridium IX Spark Plug (TR55-1IX): Enhanced Acceleration & Durability (Part No.7316)

Iridium IX Spark Plug (TR55-1IX): Enhanced Acceleration & Durability

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$16.99
NGK Iridium IX spark plugs are specifically designed for the performance enthusiast. Iridium IX provides outstanding acceleration, high fuel efficiency and durability. NGK Iridium IX plugs offer extreme ignitability and exceptional anti-fouling. Tapered cut ground electrode provides improved starting, idling and throttle response. The Iridium fine wire center electrode’s durability is six times harder than platinum. Iridium alloy’s extremely high melting point is perfect for today’s engines. For even greater performance consider upgrading to an NGK Ruthenium HX plug.

Product Features:
  • SINGLE IRIDIUM TIP: Fine wire 0.6 millimeter iridium tip center electrode ensures high durability and a consistently stable spark
  • IRIDIUM ALLOY CENTER ELECTRODE: Iridium’s density (6x that of platinum) and extremely high melting point is perfect for modern high efficiency engines
  • TAPERED CUT GROUND ELECTRODE: Reduced quenching design produces outstanding ignitability, improved acceleration, fuel efficiency and durability
  • SOLID COPPER CORE: 98% pure copper core offers superior heat dissipation, conductivity and ultra wide heat ranges
  • TRIVALENT METAL PLATING: Delivers superior anti-corrosion and anti-seizing properties, ensuring ease of installation and removal
  • RECOMMENDED USAGE: Modified or high performance applications, or as an upgrade to OE nickel alloy spark plugs
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Autolite – Platinum Spark Plug: Enhanced Durability & Performance (Part No.AP5145)

Platinum Spark Plug: Enhanced Durability & Performance

from

$4.99
Autolite Platinum spark plugs are crafted for superior performance and durability, making them ideal for older engine applications. Featuring a platinum center electrode firing tip, these spark plugs ensure quicker firing, smoother starts, better acceleration, and improved fuel efficiency. The platinum firing tip prevents gap erosion, extending the service life, while the high alumina ceramic insulator enhances thermal conductivity and insulation for added strength. Designed with a long projection standard center electrode and a nickel-plated shell, these spark plugs resist corrosion and deliver extended durability. The multi-rib insulator prevents flash-over, ensuring reliable operation, and the tapered seat type offers a secure fit. With a performance-grade design and nickel ground electrode tip material, these spark plugs are built to meet the demands of high-performance engines while maintaining consistent reliability. Whether you’re seeking enhanced efficiency or long-lasting durability, these spark plugs are a dependable choice for your vehicle.

Product Features:
  • Engineered with a platinum firing tip that prevents gap erosion for longer service life.
  • Its high alumina ceramic insulator provides thermal conductivity and superior insulation for increased strength.
  • The multi-rib insulator prevents flash-over.
  • Designed with a nickel-plated shell that is corrosion resistant to provide increased durability for extended life.
  • Built with a tapered seat type for a secure and precise fit, ensuring reliable performance and compatibility with high-performance engines.
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Motorcraft – Standard Spark Plug: Enhances Durability & Reduces Fuel Consumption (Part No.SP-409)

Standard Spark Plug: Enhances Durability & Reduces Fuel Consumption

from

$2.49
Motorcraft Spark Plugs are original equipment on Ford Motor Company vehicles, engineered to meet strict Ford engineering standards for optimal performance and reliability. These spark plugs are matched to specific engines to provide enhanced durability, eliminate misfires, reduce fuel consumption, and optimize emissions. They are resistant to oxidation and arc erosion, feature a multi-rib insulator to protect against misfire, and offer service intervals of up to 100,000 miles. Backed by Motorcraft’s Service Parts Warranty, these spark plugs are an exact fit for Ford, Lincoln, and Mercury vehicles and are designed with high-quality materials to ensure reliable performance for almost any application. Motorcraft ignition components also help prevent false check engine lights, making them a dependable choice for both domestic and import cars and trucks of all makes and sizes.

Product Features:
  • Motorcraft spark plugs are matched to specific engines to provide enhanced durability, eliminate misfires, reduce fuel consumption and optimize emissions.
  • Backed by Motorcraft’s Service Parts Warranty
  • Exact fit for Ford, Lincoln and Mercury vehicles
  • Resistant to oxidation and arc erosion.
  • Multi-rib insulator protects against misfire.
  • Service intervals of up to 100,000 miles.
  • Motorcraft Spark Plugs are designed with high quality materials to provide reliable performance for almost any application.
  • Motorcraft Spark Plugs are what was in the vehicle when it was manufactured
  • Motorcraft ignition components help prevent false check engine lights.
  • Enhanced Durability: Engineered to meet strict Ford engineering standards, these spark plugs are designed to provide long-lasting performance and withstand harsh conditions.
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Dorman – Help – Spark Plug Non-Foulers – 14mm Tapered Seat (Part No.42008)

Spark Plug Non-Foulers - 14mm Tapered Seat

from

$10.49
This spark plug non fouler is designed for easy installation on specified vehicles to protect spark plugs from fouling and damage. It is engineered for durability and reliable performance.

Product Features:
  • Direct replacement – this spark plug non fouler is designed for easy installation to protect spark plugs from fouling and damage on specified vehicles
  • Ideal solution – this non-fouler preserves spark plug life and is a reliable replacement for an original non-fouler that has failed due to corrosion
  • Durable construction – made from quality components to ensure reliable performance and a long service life
  • Trustworthy quality – backed by team of product experts in the United States and more than a century of automotive experience
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Champion – Double Platinum Power Spark Plug (RS14ZPYPB): Enhanced Durability & Performance (Part No.7407)

Double Platinum Power Spark Plug (RS14ZPYPB): Enhanced Durability & Performance

from

$6.29
Champion Double Platinum Power spark plugs are engineered for drivers seeking enhanced durability and performance. Built with a platinum fine-wire center electrode and a platinum pad ground electrode, these premium spark plugs ensure greater wear resistance and sharper spark focus for a more powerful ignition. The innovative Heat-Active alloy allows the electrodes to maintain optimal operating temperatures under all engine loads, ensuring consistent performance and reliability. The V-trimmed ground electrode further enhances spark precision, while the tapered seat design ensures a secure fit. Designed with a resistor type configuration, these spark plugs deliver stable performance and reduced interference. Ideal for those who demand premium-grade components, these spark plugs offer long-lasting performance and improved ignitability, making them a valuable upgrade for your vehicle.

Product Features:
  • Double Platinum Power – Premium Spark Plug. More Powerful Performance.
  • Platinum center and ground electrode for greater wear resistance
  • Maintains stable operating temperature under all engine loads
  • Fine-wire center electrode for greater ignitability
  • V-trimmed ground electrode promotes sharper spark focus
  • Heat-Active alloy allows electrodes to reach optimal temperature
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DENSO – Iridium TT Spark Plug: Ultimate Endurance and Power, 0.4mm Iridium Tip, IT16TT (Part No.4713)

Iridium TT Spark Plug: Ultimate Endurance and Power, 0.4mm Iridium Tip, IT16TT

from

$13.99
The Iridium TT Spark Plug combines the durability of an OE-style plug with the power and torque of high-performance engineering, making it a standout choice for drivers seeking reliability and efficiency. Featuring a 0.4mm Iridium center electrode – the world’s smallest diameter – it maximizes firing potential, while the 0.7mm needle tip ground electrode promotes higher spark energy and minimizes heat quenching. Built with DENSO’s patented Iridium-Rhodium alloy formula, it boasts the highest concentration of Iridium for unmatched durability, withstanding temperatures over 4000 Deg F. The advanced Twin-Tip Technology pairs a fine wire Iridium center electrode with a needle tip Platinum ground electrode, ensuring superior ignition and fuel efficiency. Designed to enhance fuel economy and reduce emissions, this spark plug allows you to drive farther with fewer stops. Developed to original equipment specifications and utilizing a 360-degree laser welding process, it guarantees exceptional structural strength and consistent performance. Perfect for those who demand endurance and power in every drive.

Product Features:
  • 0.4mm Iridium Center Electrode: World’s Smallest Diameter that maximizes firing potential
  • 0.7mm Needle Tip Ground Electrode: Promotes higher spark energy and less heat quenching
  • DENSO Patented Optimized Iridium-Rhodium Alloy Formula: Highest concentration of Iridium vs. competitors for greater durability
  • DENSO Patented 360 degree laser welding process: Ensuring exceptional quality bond and structural strength with the Iridium Center Electrode
  • Durability of an OE style plug combined with Power and Torque of high performance.
  • Withstands temperatures greater than 4000 degree Fahrenheit
  • Iridium TT
  • Advanced Twin-Tip Technology: Combines a Fine Wire Iridium Center Electrode with a Needle Tip Platinum Ground Electrode for superior ignition and efficiency.
  • Enhanced Fuel Economy and Lower Emissions: Designed to provide better fuel economy and reduced emissions, allowing you to drive around the Earth over 4 times.
  • Original Equipment Specification: Developed from the Super Ignition Plug (SIP) design, ensuring reliable and consistent performance.
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NGK – V-Power Nickel Spark Plug (TR55-1): Enhanced Ignitability & Performance (Part No.2683)

V-Power Nickel Spark Plug (TR55-1): Enhanced Ignitability & Performance

from

$5.99
NGK V-Power spark plugs offer reliable performance and improved ignitability over standard nickel plugs. Engineered specifically for OE applications, the special V-cut nickel alloy center electrode and concave ground electrode of NGK’s V-Power spark plug increases ignitability providing quicker starts and smoother idle. NGK’s legendary high grade alumina silicate ceramic creates a stronger insulator for optimal dielectric performance. Trivalent metal plating ensures superior anti-corrosion and anti-seizing properties.

Product Features:
  • ACTUAL OE or EQUIVALENT DESIGN: OEM quality construction nickel alloy center electrode with V-groove provides consistent performance
  • RECOMMENDED USAGE: Best for vehicles with OE nickel alloy plugs, not recommended on vehicles with factory precious metal plugs
  • NGK’s OE CERAMIC TECHNOLOGY: High grade alumina silicate ceramic creates a stronger insulator for optimal dielectric performance
  • SOLID COPPER CORE: 98% pure copper core offers superior heat dissipation, conductivity and ultra wide heat ranges
  • COLD-ROLLED THREADS: Prevents cross-threading and damage to cylinder heads
  • TRIVALENT METAL PLATING: Delivers superior anti-corrosion and anti-seizing properties, ensuring ease of installation and removal
  • Enhanced Ignitability: The V-cut nickel alloy center electrode and concave ground electrode design of NGK V-Power spark plugs provide quicker starts and smoother idle.
  • OE Application Specific: Engineered specifically for Original Equipment (OE) applications, ensuring compatibility and reliable performance.
  • V-Groove Tip Design: The unique V-Groove tip design of the TR55-1 model enhances ignitability and overall engine performance.
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DENSO – Iridium Power Spark Plug: Maximum Spark Energy, 0.4mm Iridium Tip, IT16 (Part No.5325)

Iridium Power Spark Plug: Maximum Spark Energy, 0.4mm Iridium Tip, IT16

from

$9.99
The Iridium Power Spark Plug features the world’s smallest Iridium Center Electrode at just 0.4mm, delivering unmatched spark precision for maximum combustion efficiency. Engineered with a patented 360-degree laser welding assembly process, this spark plug ensures exceptional durability and reliability under extreme conditions. Its U-groove and taper-cut ground electrode design optimizes flame propagation, enhancing engine performance and fuel efficiency. Built to withstand temperatures exceeding 4000 Deg F, it is burnished with nickel plating for superior high-temperature endurance and corrosion resistance. Designed for versatility, it offers a wide range of part numbers to fit thousands of applications, including classic and collector cars. With its Iridium tip and tapered seat type, this spark plug is the ultimate choice for drivers seeking maximum spark energy, durability, and long-lasting performance.

Product Features:
  • World’s smallest Iridium Center Electrode (0.4mm) for improved spark for maximum combustion
  • Patented 360-degree laser welding assembly process
  • U-groove and taper cut ground electrode to maximize flame propagation.
  • Withstands temperatures greater than 4000 degree Fahrenheit
  • Burnished nickel plating for high temperature endurance and superior corrosion resistance
  • Wide range of part numbers for thousands of applications, including classic and collector cars
  • Iridium Power
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DENSO – Platinum TT Spark Plug – PT16TT (Part No.4511)

Platinum TT Spark Plug - PT16TT

from

$5.99
The Platinum TT Spark Plug with its innovative Twin-Tip design ensures faster flame propagation, promoting more complete combustion for enhanced engine performance and efficiency. Crafted with a durable platinum center electrode tip, this spark plug offers exceptional longevity and consistent performance, making it a reliable choice for your vehicle. Its tapered seat type ensures a secure fit, reducing the risk of gas leakage and optimizing combustion chamber sealing. Designed for precision and durability, this spark plug not only improves ignition efficiency but also contributes to smoother engine operation and potentially better fuel economy. A perfect blend of advanced technology and robust materials, it delivers excellent value for drivers seeking long-lasting performance and reliability.

Product Features:
  • Innovative Twin-Tip design promotes faster flame propagation for more complete combustion, enhancing engine performance and efficiency.
  • Durable platinum center electrode tip ensures exceptional longevity and consistent performance over time.
  • Tapered seat type provides a secure fit, reducing gas leakage and optimizing combustion chamber sealing.
  • Precision-engineered to improve ignition efficiency, contributing to smoother engine operation.
  • Advanced design and robust materials deliver long-lasting performance and reliability for drivers.
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Motorcraft – Double Platinum Spark Plug: Reduces Fuel Consumption & Misfires (Part No.SP-482)

Double Platinum Spark Plug: Reduces Fuel Consumption & Misfires

from

$5.49
Motorcraft Spark Plugs are original equipment on Ford Motor Company vehicles, engineered to meet strict Ford engineering standards for performance and reliability. These spark plugs are matched to specific engines to enhance durability, eliminate misfires, reduce fuel consumption, and optimize emissions. With a platinum center and ground electrode tip, they are resistant to oxidation and arc erosion, ensuring long-lasting performance. The multi-rib insulator protects against misfires, and they are backed by Motorcraft’s Service Parts Warranty. Designed for exact fit in Ford, Lincoln, and Mercury vehicles, these spark plugs also help prevent false check engine lights and offer service intervals of up to 100,000 miles. Crafted with high-quality materials, Motorcraft Spark Plugs provide reliable performance for a broad range of applications, including domestic and import cars and trucks of all makes and sizes.

Product Features:
  • Motorcraft spark plugs are matched to specific engines to provide enhanced durability, eliminate misfires, reduce fuel consumption and optimize emissions.
  • Backed by Motorcraft’s Service Parts Warranty
  • Exact fit for Ford, Lincoln and Mercury vehicles
  • Resistant to oxidation and arc erosion.
  • Multi-rib insulator protects against misfire.
  • Service intervals of up to 100,000 miles.
  • Motorcraft Spark Plugs are designed with high quality materials to provide reliable performance for almost any application.
  • Motorcraft Spark Plugs are what was in the vehicle when it was manufactured
  • Motorcraft ignition components help prevent false check engine lights.
  • Engineered for Ford Vehicles: Motorcraft Double Platinum Spark Plugs are original equipment on Ford Motor Company vehicles, ensuring a perfect fit and optimal performance for Ford, Lincoln, and Mercury models.
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Motorcraft – Standard Spark Plug (AWSF44CA): Reliable Performance & Durability (Part No.SP-409-A)

Standard Spark Plug (AWSF44CA): Reliable Performance & Durability

from

$5.29
Standard Spark Plug (AWSF44CA) delivers reliable performance and durability, making it the ideal choice for maintaining your vehicle’s original equipment standards. Engineered specifically for Ford, Lincoln, and Mercury vehicles, these spark plugs ensure an exact fit while enhancing durability, reducing misfires, optimizing emissions, and improving fuel efficiency. Resistant to oxidation and arc erosion, they are built with high-quality materials to withstand demanding conditions and provide service intervals of up to 100,000 miles. The multi-rib insulator design protects against misfires, while Motorcraft ignition components help prevent false check engine lights, offering peace of mind and confidence in your vehicle’s performance. Backed by Motorcraft’s Service Parts Warranty, these spark plugs are the same trusted components found in your vehicle at the time of manufacture, ensuring compatibility and reliability for a broad range of applications, including domestic and import cars and trucks.

Product Features:
  • Motorcraft spark plugs are matched to specific engines to provide enhanced durability, eliminate misfires, reduce fuel consumption and optimize emissions.
  • Backed by Motorcraft’s Service Parts Warranty
  • Exact fit for Ford, Lincoln and Mercury vehicles
  • Resistant to oxidation and arc erosion.
  • Multi-rib insulator protects against misfire.
  • Service intervals of up to 100,000 miles.
  • Motorcraft Spark Plugs are designed with high quality materials to provide reliable performance for almost any application.
  • Motorcraft Spark Plugs are what was in the vehicle when it was manufactured
  • Motorcraft ignition components help prevent false check engine lights.
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Motorcraft – Spark Plug: Enhanced Durability & Reliable Performance (Part No.SP-482-X)

Spark Plug: Enhanced Durability & Reliable Performance

from

$8.99
Motorcraft Spark Plugs are engineered to deliver exceptional performance and reliability, making them the ideal choice for Ford, Lincoln, and Mercury vehicles. Designed with a fine wire platinum center electrode and nickel ground electrode tip, these spark plugs ensure precise ignition while resisting oxidation and arc erosion for long-lasting durability. The multi-rib insulator minimizes misfires, optimizing fuel efficiency and emissions, while service intervals of up to 100,000 miles provide unmatched convenience. As original equipment, Motorcraft Spark Plugs are crafted to meet strict Ford engineering standards, ensuring an exact fit and reliable performance for a wide range of domestic and import cars and trucks. Backed by Motorcraft’s Service Parts Warranty, these spark plugs help prevent false check engine lights, giving you confidence in your vehicle’s operation. Whether you’re maintaining your factory-installed components or upgrading for enhanced durability, Motorcraft Spark Plugs are built with high-quality materials to deliver consistent, dependable results.

Product Features:
  • Motorcraft spark plugs are matched to specific engines to provide enhanced durability, eliminate misfires, reduce fuel consumption and optimize emissions.
  • Backed by Motorcraft’s Service Parts Warranty
  • Exact fit for Ford, Lincoln and Mercury vehicles
  • Resistant to oxidation and arc erosion.
  • Multi-rib insulator protects against misfire.
  • Service intervals of up to 100,000 miles.
  • Motorcraft Spark Plugs are designed with high quality materials to provide reliable performance for almost any application.
  • Motorcraft Spark Plugs are what was in the vehicle when it was manufactured
  • Motorcraft ignition components help prevent false check engine lights.
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Motorcraft – Spark Plug: Reliable Ignition with Nickel Electrode Design (Part No.SP-409-AX)

Spark Plug: Reliable Ignition with Nickel Electrode Design

from

$4.99
This spark plug is engineered for reliable ignition performance, featuring a standard center electrode design and durable nickel construction for both the center and ground electrode tips. The nickel material ensures excellent conductivity and resistance to wear, making it a dependable choice for maintaining consistent engine performance. Its tapered seat type provides a secure fit, enhancing the seal and preventing gas leakage for optimal combustion efficiency. Designed to deliver long-lasting durability and compatibility with a wide range of vehicles, this spark plug is an excellent value for drivers seeking dependable ignition and smooth engine operation.

Product Features:
  • Engineered with a durable nickel construction for both the center and ground electrode tips, ensuring excellent conductivity and resistance to wear.
  • Tapered seat type design enhances the seal, preventing gas leakage and promoting optimal combustion efficiency.
  • Compatible with a wide range of vehicles, offering versatility and convenience for various applications.
  • Designed to deliver consistent ignition performance, supporting smooth engine operation and reliability.
  • Long-lasting durability makes it a dependable choice for maintaining consistent engine performance over time.
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Best-Selling 1991 Mercury Grand Marquis Spark Plug Wire Set Cut To Fits

Upgrade your Grand Marquis with one of our 2 best-selling Spark Plug Wire Set Cut To Fits, earning an average 3.75 stars rating across 7 reviews.

Accel – 8Mm Super Stock Graphite Uni (Part No.4040B)

8Mm Super Stock Graphite Uni

from

$71.99
ACCEL’s SuperStock 4000 series spark plug wire sets are designed to upgrade an OE ignition system for high-spark delivery levels for street driven applications. The 450 degree F rated silicone jacket is extruded over a tightly woven, rugged fiberglass braid. The braid is applied over high dielectric strength EPDM (Ethylene Propylene Diene Monomer) inner insulation for ignition wire performance that exceeds SAE specifications.

Product Features:
  • 7mm And 8mm High Gloss Silicone Jacket
  • 450 F Rated Silicone Jacket
  • Stainless Steel Plug Terminals
  • RFI Suppression For Street Driven Applications
  • Custom-fit Universal And Import Coverage
  • High-strength Fiberglass Braid Construction
  • Pre And Post HEI Vehicles
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Accel – 8Mm Super Stock Spiral Uni Bk (Part No.5040K)

8Mm Super Stock Spiral Uni Bk

from

$99.99
The traditional ACCEL combination of yellow wire and red spark plug boots has been added to these SuperStock Spiral Core 5000 Series wire sets, which feature color-matched wire and spark plug boots in blue, black, and red. With only 500 ohms/ft. of resistance, more ignition energy can reach the spark plug, producing a longer-lasting, hotter spark flame kernel. The results is higher performance through improved efficiency, quicker throttle response, and reduced emissions. This 8mm wire’s double silicone construction is rated to 550 degrees F. The high-gloss wire jacket resists moisture, chemicals, and heat extremes for longer life and great looks. The fiberglass braid adds greater pull strength and terminal retention, while the stainless steel spark plug terminals provide excellent long life, electrical conductivity, and corrosion resistance. Both universal and custom-fit applications are available for early and late model cars and trucks.

Product Features:
  • 500 Ohms/ft Of Resistance
  • 550 F Rated Silicone Jacket
  • Stainless Steel Plug Terminals
  • High RFI Suppression For Street And Strip Use
  • Universal And Import Coverage
  • High-strength Fiberglass Braid Construction
  • Pre And Post HEI Vehicles
  • 8mm High Gloss Silicone Jacket
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Top-Rated Spark Plug Brands For Your 1991 Mercury Grand Marquis

When it comes to finding the perfect Spark Plug for your 1991 Mercury Grand Marquis, Advance Auto Parts has you covered with a wide selection of high-quality OEM and aftermarket options from 7 trusted brands. We carry the most popular Spark Plug brands including NGK, DENSO, and Autolite, and more, all known for their exceptional customer ratings (average brand rating of 4.8 stars) and competitive prices, as low as $3.99. Purchasing a Spark Plug from us here at Advance Auto Parts is a smart move for both you and your 1991 Mercury Grand Marquis, providing peace of mind with parts that meet or exceed OEM standards.

Popular NGK 1991 Mercury Grand Marquis Spark Plugs

If you’re looking for a top-quality Spark Plug for your 1991 Mercury Grand Marquis, Advance Auto Parts has exactly what you need with our selection of NGK Spark Plugs. We have 3 NGK Spark Plugs in stock for this fitment, all known for their durability and precision fit. With prices starting at just $5.99 and an average cost of $10.49, you’ll find the perfect Spark Plug for your needs and budget. NGK Spark Plugs for the 1991 Mercury Grand Marquis come highly rated, with over 365 customer reviews and an impressive average rating of 4.8 stars. Choosing a NGK Spark Plug from Advance Auto Parts is a smart move to ensure quality and value for your vehicle.
Iridium IX Spark Plug (TR55-1IX): Enhanced Acceleration & Durability
from $16.99
(323)
Iridium IX Spark Plug (TR55-1IX): Enhanced Acceleration & Durability
“Awesome. I just added them together with the screaming demon coil distributor and the Taylor Performance wire kit 8.2 and my mpg went automatically 2 ”
G-Power Platinum Spark Plug (TR55-1GP): Enhanced Durability & Efficiency
from $8.49
(12)
G-Power Platinum Spark Plug (TR55-1GP): Enhanced Durability & Efficiency
“Wanting to review different items but no matter what I choose this site always goes back to the spark plugs! Already reviewed them smh.”

Top-Quality DENSO 1991 Mercury Grand Marquis Spark Plugs

For those in search of a high-quality Spark Plug for their 1991 Mercury Grand Marquis, Advance Auto Parts offers a great selection of DENSO Spark Plugs. With 3 DENSO Spark Plugs in stock, you can trust you’re getting top-tier parts designed for durability and a perfect fit. Prices for these Spark Plugs start at just $5.99, with an average price of $9.99, giving you a range of options to suit your budget. Backed by over 158 customer ratings and an average rating of 4.6 stars, DENSO Spark Plugs provide both reliability and excellent performance. Choosing a DENSO Spark Plug from Advance Auto Parts is a smart investment in your vehicle’s performance and longevity.
Platinum TT Spark Plug - PT16TT
from $5.99
(90)
Platinum TT Spark Plug – PT16TT
“Works Great”
Iridium TT Spark Plug: Ultimate Endurance and Power, 0.4mm Iridium Tip, IT16TT
from $13.99
(46)
Iridium TT Spark Plug: Ultimate Endurance and Power, 0.4mm Iridium Tip, IT16TT
“Work out great you can feel the difference and gas mpg great gain 4mpg”

FAQs for 1991 Mercury Grand Marquis Spark Plugs

What are the best-selling Spark Plugs for 1991 Mercury Grand Marquis?

Out of 18 Spark Plugs that fit 1991 Mercury Grand Marquis, the following parts are the top sellers:

What’s the price range for 1991 Mercury Grand Marquis Spark Plugs?

The prices of Spark Plugs for the 1991 Mercury Grand Marquis range from $2.49 up to $99.99 for the most premium parts.

What is the average price of a Spark Plug for a 1991 Mercury Grand Marquis?

The average price for Spark Plugs for the 1991 Mercury Grand Marquis is $19.13. Keep in mind the variety of part types within our Spark Plug category, where you are likely to find a wide range of prices across a variety of parts and components.

Does Advance Auto Parts sell Spark Plugs for other Mercury Grand Marquis model years?

Yes, we carry Spark Plugs for 35 model years of Mercury Grand Marquis between 1975 and 2011. The following model years are the most popular for Spark Plug purchases: 2011, 2010, 2009, 2008, 2007, 2006, 2005, 2004, and 2003.

What are the cheapest Spark Plugs for my 1991 Mercury Grand Marquis?

Does Advance Auto Parts sell Spark Plugs for any other 1991 Mercury models?

Yes. We stock Spark Plugs for 5 other popular 1991 Mercury models. Some of the most popular are 1991 Cougar Spark Plugs, 1991 Colony Park Spark Plugs, 1991 Sable Spark Plugs, 1991 Capri Spark Plugs, and 1991 Tracer Spark Plugs.

What are the top-rated Spark Plugs that fit the 1991 Mercury Grand Marquis?

Based on 587 reviews by customers, our 1991 Mercury Grand Marquis Spark Plugs have an average customer rating of 5 stars. These are the highest-rated categories of Spark Plugs for the 1991 Mercury Grand Marquis and their top-rated products:

What types of Spark Plugs do you sell for my 1991 Mercury Grand Marquis?

As of 11/2/25, these are some of the most in-demand types of Spark Plugs for a 1991 Mercury Grand Marquis:

Can I get help with 1991 Mercury Grand Marquis Spark Plug orders?

Contact our customer support team by chat or phone, through the help desk page, where you can find instant answers about Mercury Spark Plugs and more.

What is your return policy for Mercury Grand Marquis Spark Plugs?

Advance Auto Parts keeps returns simple. For new Mercury Grand Marquis Spark Plugs and accessories, your online orders can be returned, in their original condition, within 45 days. For requirements, see the returns page.