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 ...

If you've ever seen a mechanic draw a tiny line on a spark plug before changing it, they're not performing witchcraft — they're indexing it. The idea is simple. Most standard types of spark plugs have ...

Changing your own spark plugs is a rite of passage among gearheads. It shows you’re fully aware that your car needs basic maintenance to stay in tip-top shape, and that you’re ready to tackle it ...