2021 Subaru Legacy Spark Plugs

Keep Your 2021 Subaru Legacy 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 2021 Subaru Legacy looking sharp and performing at its best. At Advance Auto Parts we carry a wide selection of dependable options, including Spark Plugs. 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 DENSO. For example, DENSO Spark Plugs start at just $11.99 with an average 4.6 star rating. With over 51 reviews and a solid 5 star average, you can shop with confidence knowing other Subaru Legacy owners approve.

Competitive Prices and Extensive Inventory

The average price for a 2021 Subaru Legacy Spark Plug at Advance Auto Parts is around $19.49, with a range that starts at $11.99 and goes up to $26.99. With 2 options in stock from one trusted brand, finding the right fit is easy. Popular picks like Iridium Long-Life Spark Plug: Super Ignition, OE Performance, FXE22HR11 start at just $26.99 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 Coils and Boots and Ignition Sensors. At Advance Auto Parts, we’re here to help you keep your 2021 Subaru Legacy in peak condition, inside and out.

Essential 2021 Subaru Legacy Spark Plugs

ACDelco – Double Platinum Spark Plug: Long-Lasting Performance & Durability (Part No.41-801)

Double Platinum Spark Plug: Long-Lasting Performance & Durability

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$10.99
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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E3 – DiamondFIRE Automotive Spark Plug: More Power & Fuel Efficiency (Part No.E3.56)

DiamondFIRE Automotive Spark Plug: More Power & Fuel Efficiency

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$8.49
The Premium DiamondFire Automotive Spark Plug is engineered to deliver peak performance and efficiency for your vehicle. Featuring E3’s patented Diamond Fire edge-to-edge ground electrode, it ensures a faster, more complete burn for smoother acceleration and idle. The innovative “diamond-shaped” side wire electrode enhances combustion by igniting the air/fuel mixture more quickly, resulting in a larger flame kernel and improved power output – up to 6% on average. Designed with nickel center and ground electrode tips, this spark plug offers durability and consistent performance. Its cleaner-burning combustion reduces engine carbon deposits and promotes fuel savings, making it an eco-friendly choice. Pre-gapped at the factory for hassle-free installation, this spark plug is a perfect blend of advanced technology and convenience, ensuring your engine runs at its best.

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 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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DENSO – Iridium TT Spark Plug: Ultimate Endurance and Power, 0.4mm Iridium Tip, IKH20TT (Part No.4704)

Iridium TT Spark Plug: Ultimate Endurance and Power, 0.4mm Iridium Tip, IKH20TT

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$12.99
Experience the perfect blend of durability and performance with this Iridium TT Spark Plug. Engineered with a 0.4mm Iridium Center Electrode, the world’s smallest diameter, it maximizes firing potential for unmatched ignition efficiency. The 0.7mm Needle Tip Ground Electrode enhances spark energy while minimizing heat quenching, ensuring consistent performance. Built with DENSO’s patented Iridium-Rhodium alloy formula, this spark plug boasts the highest concentration of iridium for superior durability, even under extreme conditions exceeding 4000 Deg F. The 360-degree laser welding process guarantees a robust bond and structural integrity, making it a reliable choice for long-term use. Designed to deliver the durability of an OE-style plug while enhancing power and torque, this spark plug is a high-performance upgrade for your vehicle. With its flat seat type and advanced materials, it ensures optimal compatibility and efficiency, making it a valuable addition to any engine.

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
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Champion – Platinum Power Spark Plug (RC12PYC): Powerful Performance & Durability (Part No.3071)

Platinum Power Spark Plug (RC12PYC): Powerful Performance & Durability

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$4.99
Champion Platinum Power spark plugs are engineered to deliver exceptional performance and durability, making them a reliable choice for your vehicle. Featuring a platinum center electrode, these spark plugs ensure long-lasting performance and resistance to wear, maintaining the proper gap specification throughout their lifespan. The fine-wire center electrode enhances ignitability, while the V-trimmed ground electrode sharpens spark focus for optimal combustion. Constructed with the exclusive Heat-Active alloy, these plugs quickly reach and maintain the ideal operating temperature, ensuring consistent performance under various driving conditions. Designed as a standard replacement, they incorporate a nickel ground electrode tip and a resistor for enhanced functionality. Whether you’re looking for improved ignition efficiency or extended service life, these spark plugs provide excellent value and reliability for your engine.

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
  • Platinum Center Electrode: The Champion Platinum Power Spark Plug features a platinum center electrode for extended durability and long-lasting performance.
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NGK – Laser Iridium Spark Plug (IFR6E11): Fine Wire Tip for Precision (Part No.6741)

Laser Iridium Spark Plug (IFR6E11): Fine Wire Tip for Precision

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$22.99
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
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DENSO – Iridium Long-Life Spark Plug: Super Ignition, OE Performance, FK20HR11 (Part No.3426)

Iridium Long-Life Spark Plug: Super Ignition, OE Performance, FK20HR11

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$21.49
Engineered for unmatched performance, this Iridium Long-Life Spark Plug is crafted with DENSO’s patented Iridium Alloy, featuring a fine wire center electrode for superior ignition efficiency. Its Platinum Needle Tip Ground Electrode ensures higher spark energy while minimizing heat quenching, making it ideal for high-performance ignition systems. Built to endure extreme temperatures exceeding 4,000 Deg F, this spark plug is designed to last up to three times longer than conventional plugs, delivering sustained spark performance for over 100,000 miles. The 360-degree laser welding process guarantees a robust bond and structural integrity, ensuring reliability under demanding conditions. With a flat seat type and OE-level precision, this spark plug meets the highest standards for durability, emissions, and performance, making it a long-lasting and cost-effective solution for your vehicle’s ignition system.

Product Features:
  • Latest OE technology with DENSO’s patented Iridium Alloy (90 percent Ir) and fine wire center electrode
  • Platinum Needle Tip Ground Electrode: Promotes higher spark energy and less heat quenching
  • DENSO Patented 360 degree laser welding process: Ensuring exceptional quality bond and structural strength with the Iridium Center Electrode
  • Sustained spark performance over 100,000 miles
  • Lasts up to three times as long as conventional plugs
  • Endures extreme temperatures greater than 4,000 degrees F associated with high-performance ignition and special fuel systems
  • Iridium Long Life (SIP)
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Autolite Iridium – Iridium XP Fine wire Spark Plug: Improved Durability, More Focused Ignition (Part No.XP5683)

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: Offers improved durability and wear resistance for a longer-lasting spark plug.
  • Engineered in the USA: Designed with over 100 years of Autolite engineering experience for superior quality and performance.
  • Proven Track Record: Part of a legacy with over 11 billion spark plugs sold, ensuring trusted performance and reliability.
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Autolite – Double Platinum Spark Plug: Enhanced Durability & Performance (Part No.APP3924)

Double Platinum Spark Plug: Enhanced Durability & Performance

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$6.99
Double Platinum Spark Plug offers enhanced durability and performance with its platinum-to-platinum design, effectively reducing gap erosion and minimizing misfires for a longer service life. Engineered for distributor-less ignition system (DIS) engines, it outperforms copper and standard platinum plugs. The yttrium-enhanced ground electrode ensures superior heat transfer, maintaining durability under high temperatures and pressure. Its high alumina ceramic insulator optimizes thermal conductivity and dielectric strength, while the multi-rib insulator prevents flash-over for reliable operation. Featuring a mid-projection center electrode and flat seat type, this performance-grade spark plug is built with platinum-tipped electrodes for consistent ignition and lasting reliability. Designed to deliver exceptional value, it is a dependable choice for those seeking improved engine efficiency and longevity.

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 flat seat type to ensure consistent ignition and reliable performance in demanding conditions.
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Autolite Iridium – Iridium Ultra Fine wire Spark Plug: Optimal Performance & Durability (Part No.AI3923)

Iridium Ultra Fine wire Spark Plug: Optimal Performance & Durability

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$10.99
Optimal Performance, Durability, Ignitability. The Autolite Iridium Ultra is an engineered OE replacement iridium spark plug featuring a laser-welded 0.5mm proprietary iridium alloy finewire center electrode that ensures optimal fuel efficiency, acceleration, and focused ignitability. Its nickel-plated shell resists corrosion, while the high-alumina ceramic insulator provides increased strength. Additionally, the proprietary platinum sidewire technology enhances durability and performance, making it a top choice for reliable ignition. It also features a resistor type and a flat seat type for added compatibility and performance.

Product Features:
  • Autolite Iridium Ultra is an engineered OE replacement iridium spark plug.
  • A laser-welded 0.5mm proprietary iridium alloy finewire center electrode provides optimal fuel efficiency, acceleration and focused ignitability.
  • Nickel-plated shell to resist corrosion.
  • High-alumina ceramic insulator for increased strength.
  • Laser welded 0.5mm Iridium finewire center electrode.
  • Proprietary platinum sidewire technology.
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Autolite Iridium – Iridium XP Fine wire Spark Plug: Improved Durability, More Focused Ignition (Part No.XP5325)

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

from

$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: Offers improved durability and wear resistance for a longer-lasting spark plug.
  • Designed and Engineered in the USA: Reflects over 100 years of Autolite’s engineering experience and expertise.
  • Gasket Seat Type: Ensures a secure and proper fit for optimal performance.
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Autolite – Platinum Spark Plug (AP3924): Improved Performance & Durability (Part No.AP3924)

Platinum Spark Plug (AP3924): Improved Performance & Durability

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$4.99
The Autolite Platinum spark plug is a high-performance solution designed to enhance your engine’s efficiency and longevity. Featuring a platinum center electrode firing tip, it ensures quicker firing, smoother starts, and improved fuel efficiency while resisting gap erosion for an extended service life. Its high alumina ceramic insulator provides excellent thermal conductivity and superior insulation, boosting overall strength and reliability. The multi-rib insulator design prevents flash-over, while the nickel-plated shell offers exceptional corrosion resistance, ensuring durability even in demanding conditions. With a mid-projection standard center electrode and a flat seat type, this spark plug is tailored for optimal performance in older engine designs. The combination of a platinum tip and nickel ground electrode makes it a dependable choice for those seeking enhanced acceleration and long-lasting performance. Whether you’re maintaining or upgrading, this performance-grade spark plug delivers exceptional value and reliability.

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.
  • Incorporates a mid-projection center electrode and flat seat type, optimizing compatibility and performance in older engine designs.
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NGK – G-Power Platinum Spark Plug (BKR6EGP): Enhanced Durability & Efficiency (Part No.7092)

G-Power Platinum Spark Plug (BKR6EGP): 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

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
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Champion – Double Platinum Power Spark Plug (RC10PYPB4): Enhanced Ignitability & Durability (Part No.7546)

Double Platinum Power Spark Plug (RC10PYPB4): Enhanced Ignitability & Durability

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$9.99
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 a more efficient ignition process. 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 design further enhances ignitability, promoting a stable and powerful spark. Designed as a standard replacement, these spark plugs are equipped with a resistor and a flat seat type for seamless compatibility with a wide range of engines. Whether you’re looking for improved fuel efficiency or long-lasting performance, these spark plugs are built to meet your needs with precision and quality.

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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NGK – Standard Nickel Spark Plug (BKR5ES-11): Reliable OE Performance (Part No.2382)

Standard Nickel Spark Plug (BKR5ES-11): Reliable OE Performance

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$5.99
NGK Standard spark plugs (in the iconic NGK ‘yellow box’ packaging) are a proven OE cornerstone and technology customers have relied on for decades. Engineered specifically for OE applications, NGK Standard spark plugs provide OE quality nickel alloy reli

Product Features:
  • ACTUAL OE or EQUIVALENT DESIGN: OEM quality construction nickel alloy center electrode 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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Motorcraft – High-Durability Spark Plug: Reduces Misfires & Fuel Consumption (Part No.SP-485-X)

High-Durability Spark Plug: Reduces Misfires & Fuel Consumption

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$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. 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 provide reliable performance for almost any application. Motorcraft ignition components also help prevent false check engine lights, ensuring your vehicle runs smoothly.

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: Original equipment on Ford, Lincoln, and Mercury vehicles, ensuring a perfect fit and optimal performance.
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Motorcraft – Platinum Spark Plug: Enhances Durability & Reduces Fuel Consumption (Part No.SP-497)

Platinum Spark Plug: Enhances Durability & Reduces Fuel Consumption

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$7.79
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. 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 deliver 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.
  • Enhanced Durability: Engineered to meet strict Ford engineering standards, these spark plugs are designed to provide long-lasting performance with a platinum center and ground electrode tip that resist oxidation and arc erosion.
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DENSO – Platinum TT Spark Plug with Twin-Tip Design for Enhanced Ignition (Part No.4506)

Platinum TT Spark Plug with Twin-Tip Design for Enhanced Ignition

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$5.99
The Platinum TT Spark Plug features a cutting-edge twin-tip design with a platinum center electrode, ensuring superior conductivity for efficient and consistent ignition. Its titanium-enhanced ground strap adds exceptional durability, making it a reliable choice for long-lasting performance. Engineered to optimize flame propagation, this spark plug promotes more complete combustion, improving engine efficiency and power output. The flat seat type ensures a secure fit, while the advanced materials enhance ignition reliability, making it ideal for automotive enthusiasts seeking enhanced performance and durability.

Product Features:
  • Platinum Twin-Tip Design: The Denso Platinum TT Spark Plug features a twin-tip design with a high-quality platinum center electrode, ensuring excellent conductivity and enhanced ignition performance.
  • Titanium-Enhanced Ground Strap: Equipped with a titanium-enhanced ground strap, this spark plug offers superior durability and longevity, making it a reliable choice for your vehicle’s ignition system.
  • Superior Conductivity: The platinum center electrode tip provides excellent conductivity, ensuring efficient and consistent ignition for improved engine performance.
  • Enhanced Ignition System: Designed to enhance your vehicle’s ignition system, the Denso Platinum TT Spark Plug delivers superior performance and reliability, making it an ideal choice for automotive enthusiasts.
  • Optimized Flame Propagation: Engineered to promote more complete combustion, this spark plug enhances engine efficiency and power output for a smoother and more powerful driving experience.
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NGK – Laser Platinum Spark Plug (FR5AP-11): Fine Wire Tip for Precision (Part No.5463)

Laser Platinum Spark Plug (FR5AP-11): Fine Wire Tip for Precision

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$18.99
NGK Laser Platinum spark plugs provide high ignitability and longer service life compared to conventional nickel spark plugs. Laser Platinum plugs are tested to the highest standards to ensure quality and durability. Engineered specifically for OE applica

Product Features:
  • ACTUAL OE or EQUIVALENT DESIGN: OEM quality construction fine wire platinum alloy center electrode provides consistent performance
  • PLATINUM ALLOY CENTER ELECTRODE: Longer wearing and higher temperature resistance compared to traditional nickel spark plugs
  • 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 platinum alloy plugs
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NGK – Standard Nickel Spark Plug (BKR6ES-11): Reliable OE Performance (Part No.5553)

Standard Nickel Spark Plug (BKR6ES-11): Reliable OE Performance

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$6.99
NGK Standard spark plugs (in the iconic NGK ‘yellow box’ packaging) are a proven OE cornerstone and technology customers have relied on for decades. Engineered specifically for OE applications, NGK Standard spark plugs provide OE quality nickel alloy reliable performance and design. NGK’s legendary high grade alumina silicate ceramic creates a stronger insulator for optimal dielectric performance, while triple gasket sealing prevents combustion gas leakage. Solid 98% pure copper core offers superior heat dissipation, conductivity and ultra wide heat ranges. 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 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
  • Triple Gasket Sealing: Prevents combustion gas leakage, ensuring efficient engine performance.
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DENSO – U-Groove Spark Plug: OE Performance, K20HR-U11 (Part No.3381)

U-Groove Spark Plug: OE Performance, K20HR-U11

from

$7.99
The U-Groove Spark Plug features a patented U-groove ground electrode design that enhances ignitability, allowing for leaner fuel mixtures and improved engine efficiency. Built with a nickel center electrode tip and a flat seat type, this spark plug ensures reliable performance and compatibility with a wide range of vehicles, including classic and collector cars. Precision machine-rolled threads minimize the risk of seizing or cross-threading in aluminum heads, making installation smooth and secure. Designed to last twice as long as conventional plugs, it delivers over 30,000 miles of dependable operation. Each plug is 100% pre-fired to guarantee consistent performance, making it an excellent choice for maintaining OE-level performance in your engine.

Product Features:
  • Patented U-groove ground electrode design fires leaner mixtures than conventional plugs
  • Precision machine-rolled threads reduce seizing and cross-threading in delicate aluminum heads
  • Wide range of part numbers for thousands of applications, including classic and collector cars
  • Lasts twice as long as most conventional plugs
  • 100 percent pre-fired to assure reliable operation
  • U-Groove Conventional
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E3 – DiamondFIRE Automotive Spark Plug: More Power, Saves Gas (Part No.E3.68)

DiamondFIRE Automotive Spark Plug: More Power, Saves Gas

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$8.49
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. E3.68 is a 14mm, 1.000 reach plug with a gasket seat. It fits a wide variety of late model applications, especially Hemi applications. E3.68 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 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.
  • Wide Compatibility: E3.68 spark plugs are 14mm with a 1.000 reach and a gasket seat, fitting a wide variety of late model applications, especially Hemi engines.
  • Enhanced Heat Transfer: The three legs securing the Diamond FIRE electrode to the shell ensure excellent heat transfer and create more turbulence in the cylinder for better combustion.
  • Widely Available: E3.68 spark plugs are widely stocked in automotive retail stores, making them easily accessible for consumers.
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Champion – Iridium Spark Plug (RC10WYPB4): Maximum Performance & Longevity (Part No.9001)

Iridium Spark Plug (RC10WYPB4): Maximum Performance & Longevity

from

$8.49
The Champion Iridium Spark Plug (RC10WYPB4) is engineered for drivers who demand peak performance and durability. Featuring a fine-wire iridium center electrode and an iridium-platinum ground electrode, this premium spark plug ensures maximum ignitability and a sharper spark focus for enhanced engine efficiency. The V-trimmed ground electrode design promotes precise spark delivery, while the Heat-Active alloy enables the electrodes to quickly reach and maintain optimal operating temperatures under all engine loads. Built with a flat seat type and resistor technology, it provides stable performance and reduces interference. Designed for longevity, the iridium center electrode offers exceptional wear resistance, making it ideal for high-performance applications. Whether you’re looking to boost your vehicle’s power or maintain consistent performance, this spark plug delivers unmatched reliability and value.

Product Features:
  • Champion Iridium – Maximum Performance. Premium Spark Plug
  • Iridium center electrode delivers maximum life
  • Fine-wire center electrode and V-trimmed for greater ignitability
  • V-trimmed ground electrode promotes sharper spark focus
  • Maintains stable operating temperature under all engine loads
  • Heat-Active alloy allows electrodes to reach optimal temperature quickly
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ACDelco – RAPIDFIRE Spark Plug: Enhanced Durability & Performance (Part No.19)

RAPIDFIRE Spark Plug: Enhanced Durability & Performance

from

$7.99
ACDelco Gold (Professional) RAPIDFIRE Spark Plugs are a high quality alternative to Original Equipment (OE) parts. These RAPIDFIRE Single Platinum Performance Spark Plugs are designed for everyday use and are a high quality replacement for many vehicles on the road today. These premium aftermarket spark plugs have high-quality suppressors that help prevent misfiring, an improved plug to boot seal, and a pure copper core for greater durability. 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:
  • Solid state suppressor, with two-piece glass and brass seal, can help reduce radio frequency interference, regulates spark energy for long electrode life, and helps protect against high combustion pressures
  • Pure copper core provides great heat transfer and helps maximize plug durability
  • Platinum on center electrode enables superior spark characteristics and can reduce voltage requirements of the ignition system
  • Ribless insulator helps optimize plug to boot seal
  • 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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NGK – Iridium IX Spark Plug (BKR6EIX-11): Enhanced Ignitability & Durability (Part No.3764)

Iridium IX Spark Plug (BKR6EIX-11): Enhanced Ignitability & Durability

from

$14.99
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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NGK – Laser Iridium Spark Plug (SILFR6C11): High Ignitability & Durability (Part No.7505)

Laser Iridium Spark Plug (SILFR6C11): High Ignitability & Durability

from

$23.99
NGK Laser Iridium High Ignitability spark plugs offer the best combination of performance and longevity. Engineered specifically for OE applications, Laser Iridium High Ignitability spark plugs are tested to the highest standards to ensure quality and dur

Product Features:
  • ACTUAL OE or EQUIVALENT HIGH IGNITABILITY DESIGN: PSPE tip and iridium alloy center electrode produce the most advanced OE spark plug technology
  • IRIDIUM ALLOY CENTER ELECTRODE: Iridium’s density (6x that of platinum) and extremely high melting point is perfect for modern high efficiency engines
  • PSPE DESIGN: Projected square platinum electrode shape of the ground electrode provides the best ignitability and service life for high heat engines
  • 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 PSPE iridium alloy plugs
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Autolite – Platinum Spark Plug: Enhanced Durability & Improved Performance (Part No.AP3923)

Platinum Spark Plug: Enhanced Durability & Improved 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, and enhanced acceleration while boosting fuel efficiency. The platinum firing tip resists gap erosion, extending service life, while the high alumina ceramic insulator offers excellent thermal conductivity and insulation for added strength. A multi-rib insulator prevents flash-over, and the nickel-plated shell resists corrosion for long-lasting reliability. Designed with a flat gasket seat type, these spark plugs provide a secure seal for optimal engine performance. With a mid-projection standard center electrode and nickel ground electrode tip, they deliver consistent performance for demanding conditions. Perfect for performance-grade applications, these spark plugs combine advanced materials and engineering to ensure your engine runs smoothly and efficiently.

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.
  • Gasket Seat Type: Equipped with a gasket seat type, these spark plugs provide a secure and effective seal for optimal engine performance.
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NGK – V-Power Nickel Spark Plug (BKR6E-11): Reliable Ignitability & Performance (Part No.2756)

V-Power Nickel Spark Plug (BKR6E-11): Reliable Ignitability & Performance

from

$7.49
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

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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Champion – Iridium Spark Plug (RC11WYPB4): Maximum Performance & Longevity (Part No.9003)

Iridium Spark Plug (RC11WYPB4): Maximum Performance & Longevity

from

$7.49
The Champion Iridium Spark Plug is engineered for maximum performance and durability, making it a top choice for automotive enthusiasts. Featuring a fine-wire iridium center electrode and a platinum-enhanced ground electrode, this premium spark plug ensures sharper spark focus and greater ignitability for optimal engine efficiency. Its V-trimmed ground electrode design promotes consistent performance, while the Heat-Active alloy allows the electrodes to quickly reach and maintain stable operating temperatures under all engine loads. Built with a flat seat type and resistor functionality, this spark plug is designed to deliver long-lasting reliability and enhanced ignition precision. Whether you’re seeking improved fuel efficiency, smoother acceleration, or extended service life, this performance-grade spark plug is tailored to meet the demands of modern engines.

Product Features:
  • Champion Iridium – Maximum Performance. Premium Spark Plug
  • Iridium center electrode delivers maximum life
  • Fine-wire center electrode and V-trimmed for greater ignitability
  • V-trimmed ground electrode promotes sharper spark focus
  • Maintains stable operating temperature under all engine loads
  • Heat-Active alloy allows electrodes to reach optimal temperature quickly
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Most Popular Spark Plugs for 2021 Subaru Legacies

Enhance your 2021 Subaru Legacy with one of the 2 Spark Plugs we have in stock, starting at just $11.99.

DENSO – Iridium TT Spark Plug: Ultimate Endurance and Power, 0.4mm Iridium Tip, IXEH22TT (Part No.4712)

Iridium TT Spark Plug: Ultimate Endurance and Power, 0.4mm Iridium Tip, IXEH22TT

from

$11.99
The Iridium TT Spark Plug combines the durability of an OE-style plug with the unmatched power and torque of high-performance engineering. 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 reduces heat quenching. Built with DENSO’s patented Iridium-Rhodium alloy formula, this spark plug boasts the highest concentration of Iridium for superior durability, complemented by a 360-degree laser welding process for exceptional structural strength. With the ability to withstand temperatures exceeding 4000 degrees Fahrenheit, it delivers reliable performance under extreme conditions. Its advanced Twin-Tip Technology enhances fuel economy, allowing you to drive around the Earth over four times with lower emissions. Constructed with durable materials, including an Iridium Center Electrode Tip and a Flat Seat Type, this spark plug ensures robust and efficient operation, making it a smart choice for drivers seeking endurance and peak 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 and Torque of high performance.
  • Withstands temperatures greater than 4000 degree Fahrenheit
  • Iridium TT
  • Enhanced Fuel Economy: Drive around the Earth over 4 times with lower emissions and better fuel economy, thanks to the advanced Twin-Tip Technology.
  • Durable Materials: Constructed with an Iridium Center Electrode Tip and a Flat Seat Type, ensuring robust and reliable performance.
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DENSO – Iridium Long-Life Spark Plug: Super Ignition, OE Performance, FXE22HR11 (Part No.3442)

Iridium Long-Life Spark Plug: Super Ignition, OE Performance, FXE22HR11

from

$26.99
Engineered for unmatched performance, this Iridium Long-Life Spark Plug is crafted with DENSO’s patented Iridium Alloy and a fine wire center electrode, delivering exceptional ignition efficiency and durability. Its Platinum Needle Tip Ground Electrode ensures higher spark energy while minimizing heat quenching, making it ideal for high-performance ignition systems. Built to endure extreme temperatures exceeding 4,000 Deg F, this spark plug is designed to last up to three times longer than conventional plugs, maintaining sustained spark performance for over 100,000 miles. The 360-degree laser welding process guarantees a robust bond and structural integrity, ensuring reliable operation under demanding conditions. With a flat seat type and adherence to strict OE standards for performance, durability, and emissions, this spark plug offers a perfect fit and long-lasting value for your vehicle.

Product Features:
  • Latest OE technology with DENSO’s patented Iridium Alloy (90 percent Ir) and fine wire center electrode
  • Platinum Needle Tip Ground Electrode: Promotes higher spark energy and less heat quenching
  • DENSO Patented 360 degree laser welding process: Ensuring exceptional quality bond and structural strength with the Iridium Center Electrode
  • Sustained spark performance over 100,000 miles
  • Lasts up to three times as long as conventional plugs
  • Endures extreme temperatures greater than 4,000 degrees F associated with high-performance ignition and special fuel systems
  • Iridium Long Life (SIP)
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Top-Rated Spark Plug Brands For Your 2021 Subaru Legacy

When it comes to finding the perfect Spark Plug for your 2021 Subaru Legacy, Advance Auto Parts has you covered with a wide selection of high-quality OEM and aftermarket options from 1 trusted brands. We carry the most popular Spark Plug brands including DENSO, and more, all known for their exceptional customer ratings (average brand rating of 4.6 stars) and competitive prices, as low as $11.99. Purchasing a Spark Plug from us here at Advance Auto Parts is a smart move for both you and your 2021 Subaru Legacy, providing peace of mind with parts that meet or exceed OEM standards.

Popular DENSO 2021 Subaru Legacy Spark Plugs

If you’re looking for a top-quality Spark Plug for your 2021 Subaru Legacy, Advance Auto Parts has exactly what you need with our selection of DENSO Spark Plugs. We have 1 DENSO Spark Plugs in stock for this fitment, all known for their durability and precision fit. With prices starting at just $11.99, you’ll find the perfect Spark Plug for your needs and budget. DENSO Spark Plugs for the 2021 Subaru Legacy come highly rated, with over 17 customer reviews and an impressive average rating of 4.6 stars. Choosing a DENSO Spark Plug from Advance Auto Parts is a smart move to ensure quality and value for your vehicle.

FAQs for 2021 Subaru Legacy Spark Plugs

What are the best-selling Spark Plugs for 2021 Subaru Legacies?

Out of 2 Spark Plugs that fit 2021 Subaru Legacies, the following parts are the top sellers:

What’s the price range for 2021 Subaru Legacy Spark Plugs?

The prices of Spark Plugs for the 2021 Subaru Legacy range from $11.99 up to $26.99 for the most premium parts.

What is the average price of a Spark Plug for a 2021 Subaru Legacy?

The average price for Spark Plugs for the 2021 Subaru Legacy is $19.49. 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 Subaru Legacy model years?

Yes, we carry Spark Plugs for 31 model years of Subaru Legacies between 1990 and 2023. The following model years are the most popular for Spark Plug purchases: 2019, 2018, 2017, 2016, 2015, 2014, 2013, 2012, and 2011.

What are the cheapest Spark Plugs for my 2021 Subaru Legacy?

The cheapest 2021 Subaru Legacy Spark Plugs we carry are:

Does Advance Auto Parts sell Spark Plugs for any other 2021 Subaru models?

Yes. We stock Spark Plugs for 5 other popular 2021 Subaru models. Some of the most popular are 2021 Impreza Spark Plugs, 2021 WRX Spark Plugs, 2021 Crosstrek Spark Plugs, 2021 WRX STI Spark Plugs, and 2021 Forester Spark Plugs.

What are the top-rated Spark Plugs that fit the 2021 Subaru Legacy?

The one 2021 Subaru Legacy Spark Plug we have in stock is the Iridium TT Spark Plug: Ultimate Endurance and Power, 0.4mm Iridium Tip, IXEH22TT. It is rated 5 stars and costs $11.99.

What types of Spark Plugs do you sell for my 2021 Subaru Legacy?

We currently have just 1 Spark Plug in stock for a 2021 Subaru Legacy, and as of 11/2/25, it is a Spark Plug.

Can I get help with 2021 Subaru Legacy Spark Plug orders?

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

What is your return policy for Subaru Legacy Spark Plugs?

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