2021 Subaru WRX STI Spark Plugs

Enhance and Protect Your 2021 Subaru WRX STI with Quality Spark Plugs

Maintaining the performance of your 2021 Subaru WRX STI starts with choosing the right parts, and a high-quality Spark Plug helps ensure a reliable and efficient vehicle. At Advance Auto Parts, we offer Spark Plugs specifically for the 2021 Subaru WRX STI, ensuring a perfect fit and lasting durability. Choosing to shop with Advance Auto Parts means you’re making a smart decision to prioritize both quality and reliability for your vehicle.

Affordable and Reliable Spark Plugs for Every Budget

Finding a Spark Plug that combines quality with affordability is easy at Advance Auto Parts. With prices starting as low as $3.49 and an average price of $9.17, you can choose one that fits your budget while delivering the quality you expect. Our Spark Plugs are competitively priced, ranging from $3.49 to $18.99, so you get value without compromising on strength or reliability.

Trusted Brands and Top-Rated Options

With 6 Spark Plugs from 2 trusted brands in stock, Advance Auto Parts has you covered. Our Spark Plugs for the 2021 Subaru WRX STI have earned reviews from over 776 customers, with an average 5 stars rating across the board. Popular options include Iridium XP Finewire Spark Plug: Improved Durability, More Focused Ignition, Platinum Spark Plug: Fires Cleaner, Easier Starts, Quicker Acceleration, and Double Platinum Spark Plug: Platinum Firing, Superior Durability, Longer Life, starting at $4.79. Our selection includes highly regarded brands such as Autolite and NGK, and more, offering you top-notch reliability. For example, we have 5 Autolite Spark Plugs starting at $3.49 with an average rating of 5 stars, 1 NGK options from $18.99 with a 5 stars rating.

Spark Plugs for Your 2021 Subaru WRX STI

Autolite – Copper Spark Plug: Delivers Quick Starts, Good Fuel Economy, Smooth Acceleration (Part No.5325)

Copper Spark Plug: Delivers Quick Starts, Good Fuel Economy, Smooth Acceleration

from

$3.49
Autolite has over 100 years of engineering experience and has sold over 11 billion plugs. Guaranteed to deliver quick starts, good fuel economy and smooth acceleration, Autolite Copper Core spark plugs are designed to meet or exceed OES design requirements. Consider upgrading to Autolite Platinum, Double Platinum or Iridium XP plugs for improved engine performance. Copper core plugs are the industry standard.

Product Features:
  • Copper-glass seal bonds insulator, terminal post center electrode together; assures full required voltage at spark gap; gas-tight seal (100% leak proof)
  • Multi-rib insulator reduces danger of “flash-over”
  • One-piece terminal post adds strength
  • Resistor reduces radio frequency interference (RFI) and electrode erosion
  • Quick Starts: Autolite Copper Core spark plugs are engineered to ensure your engine starts quickly and reliably every time.
  • Good Fuel Economy: Designed to optimize fuel efficiency, these spark plugs help you get the most out of every gallon of gas.
  • Smooth Acceleration: Experience seamless and smooth acceleration with Autolite Copper Core spark plugs, enhancing your driving experience.
  • OES Design Compliance: These spark plugs are crafted to meet or exceed Original Equipment Service (OES) design requirements, ensuring high-quality performance.
  • Industry Standard: Autolite Copper Core spark plugs are recognized as the industry standard, backed by over 100 years of engineering expertise and the sale of over 11 billion plugs.
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NGK – OE Series Laser Iridium Spark Plug: Standard Tip Design, ILFR7H (Part No.5245)

OE Series Laser Iridium Spark Plug: Standard Tip Design, ILFR7H

from

$18.99
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.
  • High-Quality Materials: Constructed with high-grade pure alumina ceramic and a 98% pure copper core to prevent overheating and ensure reliable starts.
  • Engineered for OE Applications: Specifically designed and tested to meet the highest standards for original equipment applications.
  • Reliable Performance: Tested to the highest standards to ensure quality, durability, and consistent performance.
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Autolite Iridium – Iridium XP Finewire Spark Plug: Improved Durability, More Focused Ignition (Part No.XP5325)

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

from

$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
  • 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: Fires Cleaner, Easier Starts, Quicker Acceleration (Part No.AP5325)

Platinum Spark Plug: Fires Cleaner, Easier Starts, Quicker Acceleration

from

$4.79
With over 100 years of engineering expertise and over 11 billion plugs sold, Autolite Platinum spark plugs are designed and engineered in the USA to deliver exceptional performance. Featuring a high nickel alloy side electrode that maintains a precise gap and a full platinum tip that ensures virtually no gap erosion, these spark plugs offer long-lasting durability. The necked-down center electrode fires quicker and cleaner with less voltage, resulting in easier starts, quicker acceleration, and improved fuel economy compared to standard plugs.

Product Features:
  • High nickel alloy side electrode maintains precise gap
  • Full platinum tip assures virtually no gap erosion for long life
  • Necked-down center electrode fires quicker, cleaner with less voltage for easier starts, quicker acceleration and improved fuel economy (as compared to standard plugs)
  • Improved Fuel Economy: Designed to enhance fuel efficiency compared to standard plugs.
  • Engineered in the USA: Backed by over 100 years of engineering expertise and over 11 billion plugs sold.
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Autolite – Double Platinum Spark Plug: Platinum Firing, Superior Durability, Longer Life (Part No.APP5325)

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

from

$6.79
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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Autolite Iridium – Iridium Ultra Finewire Spark Plug: Optimal Performance, Durability, Ignitability (Part No.AI5325)

Iridium Ultra Finewire Spark Plug: Optimal Performance, Durability, Ignitability

from

$10.99
Autolite Iridium Ultra Laser Finewire Spark Plugs are one of our brand’s most technologically advanced products. These spark plugs provide superior durability, more focused ignition with better overall ignitability for optimum performance. Autolite Spark Plugs are the best alternative to OE spark plugs, offering OE fit form and function supporting all foreign and domestic makes and models at a value price. Autolite provides the automotive aftermarket and original equipment manufacturers with the highest quality ignition products and is the leading supplier of spark plugs in the world.

Product Features:
  • Autolite Iridium Ultra is an engineered OE replacement iridium spark plug.
  • A laser-welded 0.5mm pure iridium 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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FAQs for 2021 Subaru WRX STI Spark Plugs

Which Spark Plugs are the top sellers for the 2021 Subaru WRX STI?

Out of 6 Spark Plugs that fit 2021 Subaru WRX STIs, the following parts are the top sellers:

How can I make sure that a part will be compatible with my 2021 Subaru WRX STI?

Our Subaru WRX STI aftermarket and OEM parts are designed specifically for the 2021 model. You can always find your specific fitment and compatibility for your 2021 Subaru on an individual product page.

What is the price range for 2021 Subaru WRX STI Spark Plugs?

The range of prices of Spark Plugs for the 2021 Subaru WRX STI goes from $3.49 up to $18.99 for the most premium parts.

What is the average price of a 2021 Subaru WRX STI Spark Plug?

2021 Subaru WRX STI Spark Plugs average $9.17 for our selection of OEM and aftermarket parts. Keep in mind the variety of brands we offer, such as Autolite NGK, and more, so you are likely to find a wide range of prices across a variety of brands and products.

Does Advance Auto Parts sell Spark Plugs for other Subaru WRX STI model years?

Yes, we currently stock Spark Plugs for 6 model years of Subaru WRX STIs, from 2015 to 2020. Model years 2018, 2017, 2016, 2015, 2020, and 2019 are the most popular for Spark Plug purchases.

Which Spark Plugs are highest rated for the 2021 Subaru WRX STI?

Based on 776 customer reviews, our 2021 Subaru WRX STI Spark Plugs have an average rating of 5. Explore our top-rated Spark Plugs here:
Copper Spark Plug: Delivers Quick Starts, Good Fuel Economy, Smooth Acceleration
from $3.49
(1)
Copper Spark Plug: Delivers Quick Starts, Good Fuel Economy, Smooth Acceleration
“Comes pre gapped and affordable”

Can I get help with 2021 Subaru WRX STI 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 WRX STI Spark Plugs?

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