What happens if you put unleaded petrol in your car instead of leaded?

Answer 1

Where are you at? I haven't seen leaded gas or petrol since I was in grade school. They used to call it "regular" and there was that and diesel until they decided the lead in gasoline was bad for us and started offering unleaded. Eventually, every gas station in the U.S. phased regular gas out. If you have an old car from the days of leaded petrol, you'll probably have to put unleaded in it some time (unless you live in a country where they still have leaded gas at the stations). If you put unleaded gas in an old car, you can get a fuel additive to protect the engine from the harsher fuel. Over time, using unleaded in an old engine can cause some of the gaskets to dry out and start leaking. It won't hurt just one time, but it's an accumulative effect if you do it all the time.

Answer 2

Autos made within the past 25 years or so have a fuel filler opening that only permits the insertion of the small unleaded gasoline nozzle, if that is the required fuel for your auto. The larger nozzles of leaded gasoline (still used in airplanes) and diesel will not fit.

Use of leaded gasoline in modern automobiles causes the catalytic converter to malfunction and fouls the spark plugs. This, in turn, alters the operation of the engine in ways that can rapidly lead to damage. Rapidly, in this case, can mean as little as fifteen minutes. Even if the engine is undamaged, it will cost hundreds of dollars to replace the catalytic converter.