Are your spark plugs overdue for replacement? Watch for signs like poor performance, engine knocking, and decreased fuel ...

Spark plug indexing gives each spark a clearer path to ignite the air-fuel mixture, which can help tuners squeeze out a few ...

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 ...

At the HOT ROD How-To section, you’ll learn how to make improvements to your own special hot rod, drawing from the DIY knowledge of the HOT ROD team to learn more about how-to make more power from ...