Spark plug indexing sometimes is necessary to avoid side-electrode contact with high-dome pistons. Moroso offers different thickness spark plug washer kits to do this. Some theorists claim positioning ...

Modifying your spark plugs by "side gapping" is a legendary tuner trick. Does it actually boost horsepower, or is it just a myth? We checked the data.

My question is about spark plug reach. I recently removed my intake, and while looking at one valve that was near max lift, I could see the electrode was at least 1/8 inch in the threaded hole. I ...

There are a million things that make a car run like it's supposed to and there are even more that make it run like crap. One of the most essential and often overlooked components of automotive ...

Your engine’s spark plugs are one of its smallest and most important, parts. We look at some of the best. The engine in your car, truck, or crossover operates on the simple principle of capturing the ...