Gas-powered internal combustion engines need spark plugs to (literally) ignite and complete the combustion stroke, enabling the motor to produce power. They may seem unusual to the untrained eye, but ...

I had spark plugs changed in my car. The manual states replace the spark plugs at 60,000 miles. I had it done when the car had 75,000 miles.

Spark plugs are necessary for gas-powered engines. However, they're not all the same, and they can come in different shapes and sizes. Here's why that is.