What happens if you put petrol in diesel engine
It’s a heart-sinking moment at the pump: you’ve put petrol in your diesel car. This is a far more serious mistake than the other way around, and the damage can be immediate, severe, and incredibly expensive. The key is what you do next – starting the engine is the worst thing you can do.
To really get your head around what happens when you put petrol in a diesel car, you need to understand two key things: lubrication and combustion. It's easy to think of diesel as just fuel, but it’s much more than that. It's an oily, slippery substance that keeps the high-precision parts of your fuel system happy. Petrol, on the other hand, is the exact opposite. It's a solvent. It cleans things. And that one difference is where all the trouble begins.
Think about the high-pressure fuel pump and injectors in your modern diesel. These aren't just simple bits of kit; they're incredibly sophisticated, with metal components moving at blistering speeds and under pressures that can top 30,000 PSI. They absolutely rely on a constant, protective film of oily diesel to keep everything moving smoothly and stop metal from grinding against metal.
When you introduce petrol into this system, it immediately gets to work stripping away that vital oily layer. The result is catastrophic. It’s like trying to run an engine with sandpaper instead of oil. Stripped of their lubrication, those intricate metal parts start grinding against each other.
