Why cant gas cars use diesel and vice versa?


Why cant gas cars use diesel and vice versa?

In: Technology

Okay found the same post made a few hours ago

Gas cars can’t use diesel because it doesn’t burn as easily and the engine won’t run well, furthermore it’ll ruin your catalytic converter

While Diesel engines could in theory run on anything that burns, they are designed to take diesel fuel which is much more lubricating than gasoline, so the pump will break along with other stuff

They both might run on the wrong fuel for a while, but not well and not for too long

Gasoline will burn when a spark is introduced, it will ignite very easily. Diesel doesn’t ignite by a flame, making it also a bit safer. It uses high compression and leftover heat (pre glowing before starting car), a diesel enige doesn’t have spark plugs. Because of the high compression of a diesel, when you put gasoline in it, it will feel like it’s about to explode

In a diesel engine there aren’t any spark plugs, the diesel ignites just by compression, if you try to ignite diesel with a lighter you’ll see it’s much harder than gasoline. For this reason diesel engines have a high-pressure fuel pump on top of the normal fuel pump that gasoline engines have. Diesel engines have “glow plugs” which heat the cylinders before the engine starts so the diesel can ignite. It’s much worse if you put gasoline in a diesel engine than vice versa because the high-pressure pump needs lubrication from the diesel to not break. This is also the reason why it’s bad if a disel engine runs out of fuel because there will be air pockets in the fuel line that can damage the pump, some engines have an air-bleeding system thay is used if that happens. Gasoline engines on the other hand have spark plugs that create a spark every fourth stroke of each cylinder at the exact time, which is how the gasoline ignites ( or how it should, of you use lower-octane fuel it can also ignite prematurely from the pressure which is bad). The two types of engines work completely differently, so this is why they can’t run on the other fuel.

Already been answered, yet having worked on vintage tractors and such, some may find interesting that some diesel engines started up on gasoline, then switch over to diesel after warmed up.

Too, before diesel became the norm, the same thing with some with kerosene fired engines, being as, (at the time), kerosene was cheaper to run than more refined gasoline. …


The fuels have different sets of properties that are utilised in different ways in each engine type.

For example diesel is highly compressible – to ignite it inside the engines cylinder all the engine does is compress it until it combusts.

Petrol burns much more easily, so if you put petrol in a diesel engine it will compress and ignite at the wrong point in the pistons movement which will cause problems – it may run, but it won’t run well.

A petrol engine works differently – to create the ignition it uses an electrical spark, which easily ignites the very flammable fuel vapour created by petrol. Diesel doesn’t evaporate so easily however, and it won’t burn so efficiently.

In theory you could tune each engine type to run better on the opposite fuels, but because you are picking the less efficient fuel for each job, it just won’t be able to run as efficiently.