Spark plug gap guide

What the gap is

The space between the center electrode and the side electrode, where the spark jumps. Too small or too large can cause misfires.

The right gap for you

Use your vehicle's or engine's spec: the owner's manual, the label under the hood, or the engine maker. Plugs come pre-gapped by the maker, but always check before installing.

How to check it

Use a wire-type or coin-type gap gauge. The right-size wire should slide through with light drag.

Iridium and platinum plugs

Their fine center tip breaks easily. Never pry against it or slide a coin-type gauge across it; check with a wire gauge, and if it must change, bend only the side electrode, gently.

Copper plugs

Bend the side electrode in small steps with a gapping tool, then check again.

Questions?

Email info@moe-trading.com with the plug number and your engine.