What Happens If You Put Diesel In Your Petrol Car
Most petrol stations clearly mark the nozzles that are meant to pump diesel and those meant for petrol. Despite this, you can still mistakenly fill your petrol car with diesel if said nozzles are of the same size. But what would happen if you mistakenly filled your tank with this stuff?
Difference Between Diesel & Petrol
Petrol and diesel both come from crude oil. They are separated during the fractional distillation process at the refinery. At the beginning, crude oil is heated in a furnace until it’s vapourised. Then it’s sent to the distillation tower. Here, the different hydrocarbons rise through the vertical columns where they separate based on their boiling point. The former settles at a higher level than the latter.
Petrol is lighter and less dense than diesel, which allows it to flow better in the fuel system meant to facilitate its circulation. If diesel is pumped through it, as a denser and thicker liquid, it would clog up the fuel pump, fuel filter, fuel injectors and other areas.
If the diesel does make it to the engine, it would probably cause a reduction in power during the combustion process. Petrol has a flash point of -43 degrees Celsius, which means it can easily be ignited by a spark from the respective spark plug.
Diesel on the other hand, has a flashpoint of 52 degrees Celsius or higher (depends on type of diesel), which means a spark will not have the same effect on it. As such, diesel engines rely on a compression based method where the temperature is raised high enough to induce spontaneous combustion/autoignition.
What Happens When Diesel Enters The Engine?
In a petrol engine, diesel would bog its components down eventually leading to it seizing. Depending on how much diesel managed to circulate in the system, you could be looking at a cheap repair bill due to only needing to drain the tank to a costly one because of the need to change various clogged parts.
That said, it’s less of a problem compared to filling a diesel engine with petrol. Since diesel engines use a compression-based combustion system, this would lead to uncontrolled and untended combustion of petrol, which could damage the engine components. Petrol also lacks the lubrication property of diesel, which could intensify the friction on components.
Deterrents That Are Currently Used
This is why the diesel fuel filler nozzle is labeled and fitted with a metal flap to prevent the accidental filling of diesel into a petrol car’s fuel tank. Many countries have also enforced rules ensuring that the diesel fuel filler nozzles are larger than petrol ones, preventing them from fitting into a petrol car’s filler opening.
