Most drivers know that you should change your spark plugs routinely to keep your car's engine running smoothly. However, when it comes to gapping spark plugs, many people may find themselves confused.

This is an extreme Champion racing spark plug once used in 15:1 NASCAR superspeedway motors with a radically cut-back side electrode. Spark plug manufacturers usually spot-weld side electrodes to the ...

Gasoline internal combustion engines need three fundamental things: fuel, oxygen, and spark. The sexy aspects of modifying cars are focused on the first two elements: Double Pumper carburetors, ...

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.