That means that the gap can safely be pre-set during manufacture without need for change. However, if you're using a spark plug for other than its intended application, the gap may need to be ...

Although a high-performance V-8 engine’s spark plug gap requirements aren’t necessarily set in stone (with the exception of today’s modern muscle cars, like Hellcat-powered Mopars and Coyote ...

Better for side-gapping a cut-back spark plug would be an old-school round wire gapping tool, carefully inserted at about a 45-degree angle. Some prefer to use a narrow flat feeler gauge.

He created a prototype for the SPG REDUCER to offer a quick and easy way to reduce the gap of a spark plug. The tool allows the size of the required gap to be set precisely.

In summary, the majority of drivers shouldn't need to adjust the pre-set gap on an application-correct set of modern spark plugs. If you'd like to double check anyway, it certainly can't hurt and ...