What Happens if You Put Diesel in a Gas Car?

Diesel and gasoline are different types of fuel, and an engine that operates with one type isn’t compatible with the other fuel. So, what happens when you put diesel in a gas engine? Just putting diesel fuel into a gasoline car is bad enough. Attempting to drive a vehicle with diesel in a gas engine will cause it to stall as soon as diesel reaches the intake system, potentially clogging the fuel lines and damaging the engine.

Diesel is thicker than gasoline, and the more viscous fuel can clog and damage a gas engine’s injection system and other components. If you catch yourself putting diesel in a gas car, here’s what to do (and not do):

A mechanic will drain and rinse the gas tank to remove diesel and its residue. If you didn’t start the engine, that’s the only service necessary. However, additional work may be needed if you drove with diesel in the gas tank. If you ran the engine until it stalled, technicians will likely:

Incidents of putting diesel into car gas tanks are infrequent but not unheard of. To avoid mistakenly getting diesel fuel in your gas car, pay attention at the pump and don’t pick up handles with a “Diesel” label.

Human error is the reason for diesel in gas tanks. However, the mistake isn’t always the car owner’s fault. Fuel contamination can happen at the distributor level and potentially cause problems for thousands of drivers.

Consumers in Southwest Florida faced such an issue this week. A supplier provided gasoline with a strong likelihood of being contaminated with diesel fuel to at least 30 service stations in greater Tampa.

That widespread contamination accident occurred as Tropical Storm Idalia approached Florida’s west coast, as its residents were taking steps for hurricane preparation.

The best cars and best deals delivered to your inbox

Price cars, trucks and SUVs on KBB.com

Bed Liner: What To Consider for Your Truck

The Safest New Cars of 2023

Does My Car Need a New Water Pump?