What is a gasoline turbocharger

The Difference between Turbochargers on Diesel and Petrol engines.

Basically the common principles of their operation are the same as well as the way in which they intake air and exhaust gases, regardless if you are adding a turbo to a petrol or a diesel engine.

Furthermore, the basic design and components that go into petrol and diesel turbochargers are also pretty much identical.

What makes them different are :

  • the combustion pressures
  • temperatures
  • operating RPM range
  • the driving cycle

It is apparent that diesel and petrol engines differ in one way or another hence their turbochargers will need some tweaking for them to work perfectly.

First of all, we need to understand the idea behind a turbocharger.

A turbocharger is used so as to increase the amount of air and fuel that enters each combustion chamber in the engine, in order to provide additional power from each explosion.


Find Out More About ->> Difference between Turbochargers and Superchargers.


Diesel, which is not as combustible as petrol, needs higher pressure to ignite the air/fuel mix in the combustion chamber of diesel engines.

With these higher pressures, diesel engines thus need to be stronger in terms of using bigger, heavier components, which in turn makes it harder for them to operate well at higher RPMs.

What happens next is that diesel engines will need to operate at much lower and narrower RPM band as compared to petrol engines, hence making it much more to difficult draw in enough air into the combustion chambers.

The fact that diesel is also burning at a lower temperature causes it to create more exhaust gases.

Turbocharging comes into play by increasing airflow to the engine instead of increasing combustion pressures. With a larger turbine section that is capable of handling both the high volume of exhaust gases, diesel turbochargers are generally bigger and are installed for engines’ dependability and reliability..


You know that turbochargers can help you to save your fuel?

Read this article for more detail –>> Turbocharging As An Important Fuel-Saving Technology



On the other hand, being far more volatile and combustible, petrol burns hotter, ignites quicker and does not need to be atomised for combustion, therefore pressures inside the combustion chambers need not be that high. Using a lower air-to-fuel ratio than diesel fuel, petrol engines are smaller displacement engines that need to operate at a higher and wider RPM range for drivability and thus petrol burns at a higher temperature.

The addition of a turbo to petrol engines is so that the engine power will increase. Designed to run at much higher RPMs, petrol turbochargers have to spin at an incredibly high rate of speed, which subsequently provide a higher boost in pressure, without significantly increasing airflow.

Additionally, petrol turbochargers need to get up to speed more quickly due to operating at a much wider band of RPMs. As the increased RPM of both the engine and the turbocharger creates a lot of heat, many turbochargers utilise the back pressure of these hot gasses in order to improve efficiency and operation.