What happens if… Cars & Driving

Wrong fuel, warning lights, skipped maintenance and roadside surprises explained step by step.

What happens if you drive with the check engine light on?

A steady check engine light usually means "get this checked soon"; a flashing one means "pull over". Here's what the light is telling you, what can happen if you keep driving, and how to find out what's wrong for little or no money.

Costly4 min read

Cars & Driving

What happens if you put diesel in a gas car?

Putting diesel in a petrol/gasoline car is an expensive mistake only if you drive it. Don't start the engine and it's usually just a tank drain. Here's what happens in each scenario — including the reverse mistake.

Serious4 min read