2016 Honda Civic Spark Plug Type & Gap

Quick Reference

Why the right plug matters

Choosing the correct spark plug for your 2016 Honda Civic is more critical than you might think. Spark plugs are not a universal component; they are designed with specific heat ranges, materials, and gaps tailored to your engine's precise requirements.

Heat Range: The heat range of a spark plug refers to its ability to dissipate heat from the combustion chamber. A "hot" plug retains more heat, while a "cold" plug dissipates more. Using a plug that's too hot can lead to pre-ignition and engine damage, while a plug that's too cold can cause fouling and misfires. Honda engineers have meticulously selected the correct heat range for each 2016 Civic engine to optimize performance and longevity.

Electrode Metal: Modern spark plugs, especially for engines like those in the 2016 Civic, primarily use iridium or platinum electrodes. These precious metals are incredibly durable and resistant to wear, allowing for extended replacement intervals compared to traditional copper plugs.

• Iridium: Found in the OEM plugs for your 2016 Civic, iridium is one of the hardest and most corrosion-resistant metals, allowing for very fine electrodes. This fine tip concentrates the spark, improving ignition efficiency and fuel economy while also dramatically extending plug life.
• Platinum: While not typically the primary electrode material for the 2016 Civic's OEM plugs, platinum is also highly durable and can provide long service life. Some aftermarket options may use platinum-tipped electrodes.
• Copper: While copper plugs offer excellent conductivity, they wear relatively quickly due to their softer nature. You will not find copper plugs as OEM for modern engines like your 2016 Civic, as they would require much more frequent replacement than the manufacturer specified.

Using the wrong plug material can lead to premature wear, misfires, reduced fuel efficiency, and even damage to your catalytic converter over time.

How to gap a spark plug

While most modern iridium and platinum spark plugs come pre-gapped from the factory, it's always a good idea to double-check the gap before installation, especially if you're using aftermarket plugs. The gap is the distance between the center electrode and the ground electrode, and it's crucial for a strong, consistent spark.

To gap a spark plug, you'll need a spark plug gap tool, typically a coin-style or wire-style gauge.

1. Consult the Specs: Refer to the "Quick Reference" table above for the exact gap specification for your 2016 Honda Civic's engine.
2. Measure the Gap: Gently slide the appropriate thickness gauge wire or edge into the gap between the electrodes. It should fit snugly with a slight drag.
3. Adjust (if necessary): If the gap is too small, carefully use the bending tool on the gauge to slightly widen the ground electrode. If the gap is too large, gently tap the ground electrode on a clean, hard surface to close the gap. Never pry on the center electrode, as this can damage the delicate iridium or platinum tip.
4. Re-measure: Double-check the gap to ensure it's within the specified range.

Replacement procedure tips

Replacing spark plugs on your 2016 Honda Civic is a manageable DIY task for many, but a few tips can make the process smoother and prevent common pitfalls.

• Coil-on-Plug System: Your 2016 Civic utilizes a coil-on-plug (COP) ignition system, meaning each spark plug has its own individual ignition coil mounted directly over it. To access the spark plugs, you'll need to disconnect the electrical connector from each coil and then gently pull the coil straight up and off the spark plug. Be careful not to damage the wiring harness or the coil boot.
• Anti-Seize Debate: There's a long-standing debate about using anti-seize compound on spark plug threads. For modern spark plugs with nickel-plated shells (which most OEM and quality aftermarket plugs have), anti-seize is generally not recommended by manufacturers like NGK and Denso. The nickel plating provides adequate corrosion resistance and helps prevent seizing. Applying anti-seize can act as an insulator, altering the torque readings and potentially leading to overtightening or undertightening, which can damage the spark plug or cylinder head threads. If you choose to use it, apply a very thin, small amount to the threads only, and reduce the torque specification by approximately 10-20%.
• Dielectric Grease on Boots: It's highly recommended to apply a small amount of dielectric grease (non-conductive, silicone-based grease) inside the spark plug boot (the part of the coil that fits over the plug). This helps lubricate the boot for easier removal in the future, improves the seal against moisture, and prevents voltage leaks.
• Inspect Old Plugs: Before discarding your old plugs, take a moment to inspect them. Their condition can provide valuable insights into your engine's health. Look for signs of fouling (carbon buildup), oil deposits, or unusual wear patterns, which could indicate other engine issues.
• Torque Wrench is Crucial: Always use a torque wrench to tighten your new spark plugs to the manufacturer's specified torque. Overtightening can strip the threads in the cylinder head (a very expensive repair), crack the spark plug's porcelain insulator, or distort the plug shell. Undertightening can lead to plugs vibrating loose, causing misfires and potential damage to the plug or coil.

Known Issues (Not Applicable to 2016 Honda Civic Spark Plugs)

Fortunately, the 2016 Honda Civic engines (1.5L Turbo, 1.8L, and 2.0L) do not have widespread, notorious spark plug-related issues such as the two-piece spark plug breakage found in some Ford 3-valve engines or unique ionization-sensing coil problems seen in certain GM 5.3L engines. Honda's design for these engines is generally robust in this regard, provided proper maintenance and correct spark plugs are used.

Need plugs replaced? Find a shop on Repairius.