What happens when you put wrong fuel in Engine?

Mistake of putting wrong fuel in engine does not happens very often but yes we all should know the consequences.

Let us understand this in two steps, first when we put gasoline is diesel engine and second when we put diesel fuel in gasoline engine and before getting into this these are the few things we should know:

Gasoline fuel is highly volatile and has lower flash point and fire point as compared to diesel engine, which means gasoline will burn up at lower temperature than diesel. Diesel is more viscous than gasoline and has lubricating property. Diesel engine has high compression ratio as compared to gasoline engine.

Gasoline fuel in diesel engine:

Gasoline into diesel engine is very hazardous for engine than diesel into gasoline engine. When gasoline enters injection pump of diesel engine, amount of friction between moving parts increases because it’s pump is designed to use diesel as a lubricating agent and gasoline being very less viscous and not having these properties fails to do so and thus large amount of wear and tear encounters in place.

After injection of gasoline into combustion chamber there are chances of detonation and reason behind this is the lower flash point of gasoline and high compression ratio of diesel engine, due to these two parameters gasoline burns right before the end of compression stroke and results to detonation. This leads to wear and tear of engine.

Diesel fuel in gasoline engine:

When diesel gets into fuel line of gasoline engine, it gets sprayed at inlet manifold through MPFI system and gets mixed up with air. Spray nozzle of gasoline is bit different than diesel considering density of both thus injection of diesel through gasoline injector results in improper spray.

Afterwords mixture gets sucked into combustion chamber with opening of inlet valve during suction stroke. Main difference which lies between diesel and gasoline engine is the compression ratio so the air fuel mixture of diesel which requires comparatively higher compression is compressed less inside gasoline engine. Temperature which is required higher for combustion is not attained in this case and may result in misfire, but more likely engine will startup and run.