Spark Plug Gap Calculator

The correct spark plug gap depends on your engine's compression ratio, ignition system voltage, and operating conditions. Higher compression engines typically need smaller gaps (0.025-0.035"), while lower compression engines can use larger gaps (0.040-0.060").

Use a spark plug gap tool or feeler gauge to measure the distance between the center electrode and ground electrode. Insert the tool between the electrodes until you feel slight resistance - this gives you the gap measurement.

Yes, but be careful. Only bend the ground electrode (outer electrode) - never force the center electrode. Use a gap tool to gently bend the ground electrode closer or further from the center electrode to achieve the desired gap.

A gap that's too wide requires higher voltage to create a spark, which can cause misfires, hard starting, and poor engine performance. It may also cause premature ignition coil failure due to increased electrical demand.

A gap that's too narrow creates a weak spark that may not fully ignite the fuel mixture, leading to incomplete combustion, reduced power, poor fuel economy, and increased emissions.

Yes, turbocharged and supercharged engines typically require smaller gaps (0.020-0.030") due to higher cylinder pressures and temperatures, which make it harder for the spark to jump across larger gaps.

Check spark plug gaps every 30,000 miles or during regular maintenance intervals. Gaps can widen over time due to electrode wear, affecting engine performance and fuel efficiency.

Yes, incorrect gap settings can reduce fuel economy. Too wide a gap causes misfires and incomplete combustion, while too narrow a gap creates weak combustion, both leading to increased fuel consumption.