1991 Mercury Grand Marquis Spark Plugs

Essential 1991 Mercury Grand Marquis Spark Plugs

NGK – Iridium IX Spark Plug: Single Iridium Fine Wire, TR55IX (Part No.7164)

Iridium IX Spark Plug: Single Iridium Fine Wire, TR55IX

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$11.99
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 c

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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Motorcraft – Spark Plug (Part No.SP-425-X)

Spark Plug

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$5.29
The Motorcraft Spark Plug is a high-quality replacement spark plug designed to provide reliable performance and long-lasting durability for your vehicle. It features a nickel alloy electrode that provides superior wear resistance and a platinum tip that ensures consistent performance over the life of the plug. The Motorcraft Spark Plug also has a ribbed insulator design that helps prevent misfires and a copper core that provides efficient heat transfer. It is designed to meet or exceed OEM specifications and is compatible with a wide range of vehicles. Whether you’re looking to replace worn-out spark plugs or upgrade to a higher-quality option, the Motorcraft Spark Plug is an excellent choice that will help keep your engine running smoothly and efficiently.
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NGK – OE Series V-Power Nickel Spark Plug: V-Groove Tip Design, UR45 (Part No.6945)

OE Series V-Power Nickel Spark Plug: V-Groove Tip Design, UR45

from

$4.99
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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E3 – DiamondFIRE Automotive Spark Plug: More Power, Saves Gas (Part No.E3.42)

DiamondFIRE Automotive Spark Plug: More Power, Saves Gas

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$7.49
The Spark Plugs are the product of years of fundamental research in the combustion field. The unique patented electrode configuration of these new The spark plugs increases the amount of combustion pressure created during each power stroke of an engine, which results in a marked increase in power output, fuel economy, and reduced emissions in all gasoline engines. E3.42 is a 14mm, 0.460 reach plug with a taper seat. It fits domestic applications in the 80s to early 90s, and is widely stocked in automotive retail stores. The automotive plugs have three legs securing the Diamond FIRE electrode to the shell. This allows for excellent heat transfer, and helps to create more turbulence in the cylinder. The patented Diamond FIRE side wire is proven to increase power, reduce fuel consumption and improve hydrocarbon emissions in long-term use.

Product Features:
  • E3’s Diamond Fire edge to edge ground electrode provides maximum performance with increased efficiency and a faster more complete burn.
  • Smoother Acceleration & Idle – The faster flame initiated by the The spark plug results in a more complete burn of the ingested fuel charge. More pressure is created against the piston more fuel is put to work
  • Energy – Power output improved up to 6% on average in the typical operating ranges. Results will vary.
  • Efficiency – The “diamond shaped” side wire electrode projects the combustion spark in a way that more quickly ignites the air/fuel mixture, thereby creating a significantly faster and larger flame kernel. The result is that more fuel is put to work durin
  • E3’s patented Diamond Fire Technology provides a cleaner burning combustion, which translates into fuel savings and reduced engine carbon deposits
  • The Spark Plugs are pre-gapped at the factory and cannot be adjusted.
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Motorcraft – Spark Plug (AWSF44CA) (Part No.SP-409-A)

Spark Plug (AWSF44CA)

from

$5.29
Motorcraft Spark Plugs are original equipment on Ford Motor Company vehicles engineered to meet strict Ford engineering standards to provide original equipment performance and reliability. Delivering performance, reliability and confidence, Motorcraft spa

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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Autolite Iridium – Iridium XP Finewire Spark Plug: Improved Durability, More Focused Ignition (Part No.XP103)

Iridium XP Finewire Spark Plug: Improved Durability, More Focused Ignition

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$9.99
Our best spark plug! 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
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ACDelco – Double Platinum Spark Plug (Part No.41-803)

Double Platinum Spark Plug

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$9.79
ACDelco Gold (Professional) Double Platinum Spark Plug are a high quality alternative to Original Equipment (OE) parts. With a copper core and double platinum pads on the center electrode, these plugs are designed to deliver long-lasting performance. These premium aftermarket replacement spark plugs are manufactured to meet your expectations for fit, form, and function. ACDelco Gold (Professional) parts are manufactured to meet your expectations for fit, form, and function, making them a smart choice for General Motors vehicles, as well as most makes and models, including special applications. These high-quality parts are backed by General Motors. Some ACDelco Gold parts may have formerly appeared as ACDelco Professional.

Product Features:
  • One-piece, fired-in suppressor seal blends three glass types for a gas-tight seal that helps reduce radio frequency and engine interference, regulate spark plug energy, and protect against compression pressures for long life
  • Double platinum point pad on center and ground electrode offer excellent durability and consistent voltage demands to help reduce wear on ignition system
  • Pure copper core results in cooler electrode temperature for maximized durability and fouling resistance
  • Some ACDelco Gold parts may have formerly appeared as ACDelco Professional
  • Premium aftermarket replacement part
  • Manufactured to meet specifications for fit, form, and function for General Motors vehicles as well as most makes and models
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Motorcraft – Spark Plug: Enhances Durability & Reduces Fuel Consumption (Part No.SP-425)

Spark Plug: Enhances Durability & Reduces Fuel Consumption

from

$2.79
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. Resistant to oxidation and arc erosion, they feature a multi-rib insulator to protect against misfires and offer service intervals of up to 100,000 miles. Designed with high-quality materials, Motorcraft Spark Plugs ensure reliable performance for a broad range of applications, including domestic and import cars and trucks of all makes and sizes. Backed by Motorcraft’s Service Parts Warranty, they are an exact fit for Ford, Lincoln, and Mercury vehicles, helping to prevent false check engine lights and providing the same quality as the original components installed during manufacturing.

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.
  • Fuel Efficiency: These spark plugs help reduce fuel consumption, optimizing emissions and contributing to a more efficient engine performance.
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Champion – Platinum Power Spark Plug: Powerful Perfromance, OE Replacement, RS10PYC4 (Part No.3401)

Platinum Power Spark Plug: Powerful Perfromance, OE Replacement, RS10PYC4

from

$4.49
Champion Platinum Power spark plugs deliver powerful performance. Made from exclusive Heat-Active alloy, a fine-wire center electrode and V-trimmed ground electrode provides sharp spark focus.

Product Features:
  • Platinum Power- Premium Spark Plug. Powerful Performance.
  • Platinum center electrode for long life
  • 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 tipped center wire resists wear and helps to maintain proper gap spec over life of the plug
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Autolite – Double Platinum Spark Plug: Platinum Firing, Superior Durability, Longer Life (Part No.APP5145)

Double Platinum Spark Plug: Platinum Firing, Superior Durability, Longer Life

from

$6.49
Autolite has over 100 years of engineering experience and has sold over 11 billion plugs. Designed and engineered in the USA, Autolite Double Platinum spark plugs feature platinum-to-platinum firing which virtually eliminates gap erosion, reduces misfires and increases durability of the plug. Consider upgrading to Autolite Iridium XP spark plugs for increased performance.

Product Features:
  • Works to optimize engine performance for a longer life and improved fuel economy
  • OE design
  • Full-platinum tips; platinum on both the center and side electrodes to promote reduced gap wear
  • Platinum ball welding process provides a consistent point of contact for enhanced adhesion
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ACDelco – Double Platinum Spark Plug (Part No.41-816)

Double Platinum Spark Plug

from

$9.49
ACDelco Gold (Professional) Double Platinum Spark Plug are a high quality alternative to Original Equipment (OE) parts. With a copper core and double platinum pads on the center electrode, these plugs are designed to deliver long-lasting performance. These premium aftermarket replacement spark plugs are manufactured to meet your expectations for fit, form, and function. ACDelco Gold (Professional) parts are manufactured to meet your expectations for fit, form, and function, making them a smart choice for General Motors vehicles, as well as most makes and models, including special applications. These high-quality parts are backed by General Motors. Some ACDelco Gold parts may have formerly appeared as ACDelco Professional.

Product Features:
  • One-piece, fired-in suppressor seal blends three glass types for a gas-tight seal that helps reduce radio frequency and engine interference, regulate spark plug energy, and protect against compression pressures for long life
  • Double platinum point pad on center and ground electrode offer excellent durability and consistent voltage demands to help reduce wear on ignition system
  • Pure copper core results in cooler electrode temperature for maximized durability and fouling resistance
  • Some ACDelco Gold parts may have formerly appeared as ACDelco Professional
  • Premium aftermarket replacement part
  • Manufactured to meet specifications for fit, form, and function for General Motors vehicles as well as most makes and models
See More

NGK – OE Series V-Power Nickel Spark Plug: V-Groove Tip Design, TR55 (Part No.3951)

OE Series V-Power Nickel Spark Plug: V-Groove Tip Design, TR55

from

$4.99
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 model enhances ignitability and overall engine performance.
  • Lower Emissions: The NGK Laser Platinum Spark Plug contributes to lower emissions, supporting a cleaner and more environmentally friendly driving experience.
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DENSO – Iridium TT Spark Plug: Ultimate Endurance and Power, 0.4mm Iridium Tip, last 100K+ Miles, IT20TT (Part No.4714)

Iridium TT Spark Plug: Ultimate Endurance and Power, 0.4mm Iridium Tip, last 100K+ Miles, IT20TT

from

$10.99
Durability of an OE style plug combined with Power & Torque of high performance.

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 & Torque of high performance.
  • Withstands temperatures greater than 4000° Fahrenheit
  • Iridium TT
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Motorcraft – Platinum Spark Plug: Enhances Durability & Reduces Fuel Consumption (Part No.SP-493)

Platinum Spark Plug: Enhances Durability & Reduces Fuel Consumption

from

$9.29
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 provide enhanced durability, eliminate misfires, reduce fuel consumption, and optimize emissions. Backed by Motorcraft’s Service Parts Warranty, they are an exact fit for Ford, Lincoln, and Mercury vehicles and are resistant to oxidation and arc erosion. The multi-rib insulator protects against misfire, and with service intervals of up to 100,000 miles, these 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, and their ignition components help prevent false check engine lights. Featuring platinum center and ground electrode tips, these spark plugs deliver the performance, reliability, and confidence you expect.

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.
  • High-Quality Platinum Tips: Featuring platinum center and ground electrode tips, these spark plugs offer superior performance and resistance to oxidation and arc erosion.
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Accel – 8.8Mm Spiral Universal Fit (Part No.8033)

8.8Mm Spiral Universal Fit

from

$153.99
These ACCEL 8.8mm wires feature a carbon/graphite core that virtually eliminate RFI noise while providing maximum conductivity for ultimate performance in any race or street application. Double silicon insulation eliminates leakage and misfire.

Product Features:
  • 500 Ohms/ft Of Resistance
  • 550 F Rated Silicone Jacket
  • Stainless Steel Plug Terminals
  • Custom-fit Universal And Import Coverage
  • Pre And Post HEI Vehicles
  • Magnetic Suppression
  • Fiberglass/Kevlar Core
  • 500 Ohms Resistance
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MSD Ignition – Wire Set; Super Conductor; 8-cyl. Multi-Angle Plug; Socket/HEI (Part No.31199)

Wire Set; Super Conductor; 8-cyl. Multi-Angle Plug; Socket/HEI

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$129.99
Set includes terminals for engines with early type (socket) and late type (HEI spark plug top) distributor caps. 90 degree boots and terminals factory installed on one end.

Product Features:
  • Extra Long 8.5mm Wires So You Can Cut To Your Designed Length
  • Incl. both socket-style and spark plug-style boots and terminals
  • Includes Mini-Stripper-Crimper For Factory Style Crimps
  • Size Includes: [2]48/50/56 in./[3] 32 in. Wires/Boots/Terminals
  • Durable outer sleeve is a proprietary compound for resistance to high heat or abrasion
  • Stainless steel terminals feature dual crimp tabs to grip wire conductor and outer jacket separately
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MSD Ignition – Wire Set; Super Conductor; Multi-Angle Plug; HEI Cap (Part No.31189)

Wire Set; Super Conductor; Multi-Angle Plug; HEI Cap

from

$129.99
For engines with late-model type (HEI spark plug top) distributor caps. Multi-angle boots and terminals installed on one end. 90 degree distributor boots and terminals included.

Product Features:
  • Extra Long 8.5mm Wires So You Can Cut To Your Designed Length
  • Distributor Cap – Boots and Terminals Included
  • Includes Mini-Stripper-Crimper For Factory Style Crimps
  • Size Includes [8] 90 Degree Boots/Terminal Ends
  • Durable outer sleeve is a proprietary compound for resistance to high heat or abrasion
  • Stainless steel terminals feature dual crimp tabs to grip wire conductor and outer jacket separately
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1991 Mercury Grand Marquis Spark Plugs

Maybe you’re in the middle of a full rebuild of that 1991 Mercury Grand Marquis. Maybe you just need a couple of Spark Plugs. Either way, Advance Auto Parts has 27 different Spark Plugs in our inventory ranging from $2.49 to $153.99. That means you can find the exact parts or products you need to keep that 1991 Mercury Grand Marquis running smoothly.

Spark Plugs are only as good as their brand. We stock 9 different brands to make sure you have plenty of trusted parts to choose from for your 1991 Mercury Grand Marquis. DENSO, NGK, and Autolite are just some of the brands we stock. Search for brands you know or compare prices and reviews to help you decide!

We know you’ll find the perfect Spark Plugs for your 1991 Mercury Grand Marquis, but don’t take our word for it – read our customer ratings and reviews and buy with confidence. Out of the 585 reviews in this category, some of the top rated parts include PT16TT Platinum TT Spark Plug with 4.6 stars and Standard Spark Plug: Enhances Durability & Reduces Fuel Consumption with 5.0 stars.

So if you’re in the market for aftermarket Spark Plugs to keep your 1991 Mercury Grand Marquis rolling for years to come, look no further. Shop online and have your products shipped direct to your door, or pick up at the nearest Advance Auto Parts location today!

Spark Plugs Brands To Make Your 1991 Mercury Grand Marquis Last

Simple repair, complete replacement, or a full rebuild. No matter the job, your 1991 Mercury Grand Marquis demands trusted brand parts and products to keep it running. Many trusted brands of Spark Plugs make up Advance Auto Parts’ inventory, and all are ready to help make your Grand Marquis the best it can be. Be sure to browse some of our top Spark Plugs brands and parts.

FAQs for 1991 Mercury Grand Marquis Spark Plugs

What are the most purchased Spark Plugs for the 1991 Mercury Grand Marquis?

Out of 27 Spark Plugs for the 1991 Mercury Grand Marquis, the most popular in our inventory are:

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

Top-rated Spark Plugs for your 1991 Mercury Grand Marquis based on customer reviews/ratings are:
PT16TT Platinum TT Spark Plug
from $5.99
(90)
PT16TT Platinum TT Spark Plug
“On line”
Standard Spark Plug: Enhances Durability & Reduces Fuel Consumption
from $2.49
(4)
Standard Spark Plug: Enhances Durability & Reduces Fuel Consumption
“OE plugs. Same part installed when the engine rolled off the assembly line.”
Double Platinum Spark Plug: Reduces Fuel Consumption & Misfires
from $5.49
(3)
Double Platinum Spark Plug: Reduces Fuel Consumption & Misfires
“Great plug but check your gap”