We may receive a commission on purchases made from links. When it comes to engine care 101, a spark plug replacement — also referred to as a tune-up — is an essential task. Spark plugs ...

When, though, and why? First, let's define what a spark plug is, why it's important, and why it fails. Internal combustion engines need three basic elements to work — fuel, air, and spark.

A search on the internet suggests that over time galvanic corrosion between the steel spark plug threads and the aluminum cylinder heads could make removal of the plugs difficult but the anodic ...