2016 Subaru Crosstrek Spark Plug Type & Gap

Quick reference

Why the right plug matters

Choosing the correct spark plug for your 2016 Subaru Crosstrek is crucial for optimal engine performance, fuel efficiency, and longevity. Spark plugs are not a "one size fits all" component; they are specifically engineered for different engines. Key factors include heat range and electrode material.

Heat Range: This refers to the plug's ability to dissipate heat from the combustion chamber. A plug that is too "cold" (dissipates heat too quickly) can lead to fouling, while a plug that is too "hot" (dissipates heat too slowly) can cause pre-ignition and engine damage. The NGK SILZKAR7B11 specified for your Crosstrek's 2.0L FB20D engine has the correct heat range to maintain optimal operating temperatures.

Electrode Metal:

• Iridium: This is the most common and recommended material for modern engines like your Crosstrek's. Iridium plugs offer exceptional durability and a long lifespan, typically lasting 60,000 to 100,000 miles. Their fine-wire electrode design promotes a stronger, more consistent spark.
• Platinum: Platinum plugs are also durable and offer a longer lifespan than copper, usually around 50,000 miles. They are a good upgrade from copper but generally don't match the performance or longevity of iridium.
• Copper: While excellent conductors, copper plugs have a much shorter lifespan, typically requiring replacement every 15,000-30,000 miles. They are rarely specified for modern engines due to their lower durability.

Using the recommended iridium plugs ensures your Crosstrek runs smoothly and efficiently for longer, reducing the frequency of replacements.

How to gap a spark plug

Correct gapping of your spark plugs is essential for a strong spark. The gap is the distance between the center and ground electrodes. For your 2016 Subaru Crosstrek with the 2.0L FB20D engine, the recommended gap is 0.044 inches (1.1 mm). While modern iridium plugs often come pre-gapped from the factory, it's always a good practice to double-check.

Tools: You'll need a wire-type spark plug gapping tool. Avoid disc-style gappers, as they can damage the delicate iridium electrode.

Procedure:

1. Carefully slide the correct feeler wire of your gapping tool into the spark plug gap.
2. It should slide in with a slight drag. If it's too tight, gently bend the ground electrode outwards using the gapping tool's adjustment notch. If it's too wide, carefully tap the ground electrode on a hard, flat surface to slightly close the gap. Never bend the center electrode.
3. Re-check the gap until it meets the specification.

Replacement procedure tips

Changing spark plugs on your Subaru Crosstrek's horizontally opposed "boxer" engine can be a bit more challenging due to limited access. Here are some tips to make the job easier:

• Cool Engine: Always work on a cool engine. Attempting to remove spark plugs from a hot engine can damage the cylinder head threads.
• Coil-on-Plug Removal: Your Crosstrek uses a coil-on-plug (COP) ignition system. To access the spark plugs, you'll need to disconnect the electrical connector from each ignition coil and then carefully unbolt and remove the coil. Be gentle with the electrical connectors to avoid breakage.
• Extension and Swivel: Due to the engine's layout, you'll likely need a variety of extensions and a swivel joint for your socket wrench to reach all the plugs, especially those on the passenger side.
• Anti-Seize Debate: There is ongoing debate about using anti-seize on spark plug threads. For plugs with nickel-plated shells, like the NGK plugs specified for your Crosstrek, anti-seize is generally not recommended. The nickel plating provides adequate corrosion protection, and anti-seize can alter the torque readings, potentially leading to over-tightening and plug or cylinder head damage. Always follow the spark plug manufacturer's recommendations.
• Dielectric Grease: Apply a small amount of dielectric grease inside the spark plug boots (the part that connects to the top of the spark plug). This helps to seal out moisture, prevents corrosion, and makes future removal easier.
• Torque Wrench: Use a torque wrench to ensure the spark plugs are tightened to the correct specification of 15.2 lb-ft (20.6 Nm). Over-tightening can damage the plug or the cylinder head, while under-tightening can lead to compression leaks and misfires.

Known issues

Fortunately, the 2016 Subaru Crosstrek's 2.0L FB20D engine is not known for specific, widespread spark plug issues like the Ford 3-valve engine's breaking two-piece plugs or the GM 5.3L engine's ionization-sensing coils, which require specific plug types. The primary concern is simply ensuring you use the correct iridium spark plugs and follow the recommended replacement interval to maintain optimal performance.

Need plugs replaced? Find a shop on Repairius.