ARE SPECIAL PLUGS NECESSARY ON A MODIFIED ENGINE? It depends on the modifications. The term “modified” refers to those engines with bolt-on components that may or may not raise the total compression ratio of the engine. These can include turbocharging,…

DO I NEED TO SET THE “GAP” WHEN INSTALLING A NEW SET OF PLUGS? Maybe. A spark plug part number might fit hundreds of different engines from many different manufacturers. Although the NGK factory will set the gap to a preselected setting, this…

WHY ARE THERE DIFFERENT HEAT RANGES? It is a common misconception that spark plugs create heat. They don’t. the spark plug heat range only indicates the rate at which the spark plug dissipates its firing end heat to the engine. Selecting a spark…