Something about engine spark plugs that rarely seems to get mentioned is indexing. What is it, actually? Should you index the spark plugs on your engine?

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 ...

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 ...

In the past, car parts used to be rather finicky. You had to occasionally adjust the carburetor to ensure your car was getting the right amount of fuel. You had to check the coolant every season to ...