Services
Insurance
Loans
Repairs
Advice
About

What happens if you put the wrong gas in a car?

I tried to be nice by filling up my dad’s car after I borrowed it, but I admittedly bought the cheapest gas at the pump. When I mentioned I had gassed up, my dad checked that I had used “premium” fuel. I lied and said yes! What could happen if I put the wrong type of gas in his car?

avatar
Laura Salvas · Updated on
Reviewed by Shannon Martin, Licensed Insurance Agent.
While using the wrong grade of gasoline may cause at worst a minor nuisance, the wrong type of fuel can cause a major disaster. Here’s what happens if you put the wrong gas in a car:
  • High octane gas in a car needing regular fuel: Nothing bad will happen, but
    you’ll have paid more
    for no reason.
  • Low-octane gas in a car needing premium fuel: The car will still operate potentially with significantly reduced power.
  • Diesel in a gasoline vehicle or vice versa: Do not start the engine or turn the key. This will send the wrong fuel through the engine and your repair costs will skyrocket. Call a mechanic immediately as all fuel will have to be drained and cleaned from the vehicle.
Car engines have different
levels of compression
. Most cars use regular compression in their engines, so they run on regular-grade gasoline. But engines with higher compression operate better with a higher octane fuel, meaning they should use mid- or premium-grade gas.
Generally, cars operate on one type of fuel, which is noted in the owner’s manual or inside the fuel door.
Diesel is thicker than gasoline and toxic if put in a gasoline engine. Likewise, gasoline is too explosive for a diesel engine to manage. It’s difficult to accidentally put diesel in a gasoline tank as diesel pumps are seperated from gasoline pumps and the nozzle is too wide to fit your car.
Because mishaps happen, finding excellent
car insurance
is a necessity. This is easy with
Jerry
, a
super app
that helps fill up your bank account with savings by comparing policies from top insurers. Just answer a few quick questions, check out your coverage options, and potentially save more than $800 just by switching policies!
View full answer 
WHY YOU CAN TRUST JERRY
Jerry partners with more than 50 insurance companies, but our content is independently researched, written, and fact-checked by our team of editors and agents. We aren’t paid for reviews or other content.

Join 4M+ members in lowering their car insurance

Easiest way to compare and buy car insurance

√
No long forms
√
No spam or unwanted phone calls
√
Quotes from top insurance companies
Find insurance savings