Setting the gap on spark plugs

When installing new spark plugs, the correct gap is important to the vehicle's performance. In most cases, the spark plug for your application should have the correct gap and require no adjustment. It is always good practice to inspect each spark plug before installation.

Traditionally, a coin-style gap tool such as this has been a standard tool used to adjust the gap of the spark plug. For new precious-metal plugs, we do not advise the use of this tool. We recommend the use of a wire-style gap tool available in the specialty tool section of most auto parts stores. This tool can safely adjust and inspect the gap on even precious-metal spark plugs. A feeler gauge style spark plug tool will also do this job.

Now that we have the correct tools, we can adjust the gap of our spark plugs. We can check the gap using the wire loops on a gap tool.

If adjustment is required, using the back of the tool we can open or close the gap.

If we use a coin-style gap tool to open the gap of the spark plug, it is likely to break the tip. If the plug tip is broken, don't use it. Throw it away and start over with a new spark plug.

For specific gap information, consult the emissions tag under the hood of the equipment or your owner's manual.

Get your NGK spark plugs.

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