What Does It Mean To Gap a Spark Plug?

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If you’ve experienced reduced fuel economy, starting troubles or need to replace your spark plug, it’s important that you understand how to properly gap your spark plug. Use a free VIN lookup tool today to find the exact spark plug you need for your vehicle and use these tips to gap your new spark plug or maintain your current plug.

The Importance of a Proper Spark Plug Gap

Spark plugs use two electrodes that are separated an exact distance to create a spark. The distance depends on your make and model of vehicle and alters the voltage of the arc sent between the electrodes. A small adjustment in the gap can alter the voltage and even prevent the arc from successfully connecting.

Most modern spark plugs come pre-gapped. As long as you purchase a spark plug designed for your specific vehicle, you shouldn’t have to worry about adjusting the gap before installation.

However, older spark plugs and used spark plugs may not be properly gapped. As your spark plug ages, the continuous arcing can alter the distance between the electrodes. This can decrease the efficiency of your spark plug and eventually cause it to stop working altogether. Before replacing a spark plug that isn’t working, be sure to check the gap.

Gapping Tools

Because of the two basic types of spark plugs, there are a few kinds of gapping tools available. The most common tool is a coin-style gapping tool. This small tool is a great item to have on your keychain and is easy to use for most spark plug applications. It allows you to measure and adjust the gap with reasonable accuracy.

An even more precise tool is a wire-style or feeler gauge gap tool. There are many tools that fit in this category, and they typically use separate adjusting and measuring tools. They offer the precision you need and the careful adjusting necessary for precious metal coated spark plugs.

How to Gap a Spark Plug

To begin, inspect your spark plug for signs of damage. A cracked spark plug won’t operate efficiently even with a correct gap. Use your gap tool to measure the current gap and consult your service manual for the correct distance for your vehicle.

Carefully bend the spark plug electrode open or shut to arrive at the ideal gap. Don’t attempt to bend it with your hands or a separate tool, but use the specialized spark plug tool for the job. Continue to measure and refine the gap until it’s within the correct levels.

A copper electrode spark plug will resist much more bending than a precious metal coated option. These newer spark plugs are more efficient, but also more prone to breaking and other damage.

Find the Tools and Advice You Need

Compare spark plug gap tips, tricks and tools online and find the best gap tool for your needs. Shop online or visit your trusted auto parts store for an affordable and reliable tool for the job. Don’t let a minor gap issue affect your fuel economy or stop your vehicle in its tracks.

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