Asked by: Alastair Bloomfield, Ramsey
If you put diesel in a petrol engine, it’d cause knocking, which would eventually cause serious damage.
As for diesel engines, they use the fuel itself as a lubricant. Using petrol would eventually cause wear on the engine and corrode seals.
Diesel engines are stronger than petrol ones, so on balance it’s probably worse to put diesel in a petrol engine.
Read more:
- Do petroleum products like petrol and diesel have a shelf-life?
- At what speed do hybrid cars switch from battery power to petrol power?
Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun science facts.