The Differences between Petrol and Diesel Engines
The differences between petrol and diesel engines we all know that diesel engines are lower revving and more fuel-efficient than petrol engines but do you know exactly how and why they are different, if not, let this article be your ultimate guide, petrol AKA gasoline and diesel engines operate on the same four-stroke cycle, this starts with the intake strokes with a piston descends sucking air into the cylinder through air intake valves as fuel is injected this is followed by the compression stroke
Where the valves closed and the piston goes back off the cylinder to compress the air and fuel mixture the third step is the power stroke where the mixture is ignited to force the piston back down the cylinder and the final exhaust stroke occurs where the ignited fuel and mixture is pushed back out of the cylinder by the piston through the exhaust valves where petrol and diesel engines differ is how they ignite the air and fuel to understand the difference we need to understand the ignition temperature this is the temperature at which an air-fuel mixture will ignite without the use of a spark plug purely due to compression.
It’s this compression that allows the air and fuel mixture to ignite in a diesel engine without the need of a spark because the greater compression the higher the temperature that’s why these Alegent have higher compression ratios compared with petrol engines that don’t compress the air and fuel mixture to the point of ignition if you don’t know what compression ratio is let me quickly explain simply put it’s the ratio of the maximum to minimum volume in the cylinder so a ratio of 10 to 1 means that when the piston is at its lowest point.
There is ten times as much volume as when it’s at its highest point to give you an example of compression ratios a 2015 VW Golf TSI has a compression ratio of nine point six to one while a 2015 VW Golf TDI has a compression ratio of 16 points two to one again a diesel will have a higher compression ratio to ensure that the air and fuel mixture is compressed enough to the point of ignition while a petrol engine uses less compression and is ignited by the spark plug though no longer true for all modern oil burners another significant difference
Where the diesel vs. petrol engine is that Dessel’s Lacus throttle body means that when you press on the accelerator pedal the more powerful petrol or gasoline engines, on the other hand, require a throttle body as you press on the accelerator pedal you open up the throttle and allow more air to flow into the engine more air means the injectors send in more fuel and war fuel injectors simply supply more diesel to create fuel needs power, where petrol and diesel engines differ again, is how they are able to enter great where you lift off the throttle in gear to slow the car down in a petrol vehicle engine braking is because as you lift off the throttle the throttle body closed creating a vacuum between the throttle body and the cylinders to slow the car down