You’ll often see the TDI badge on many diesel cars but what does it actually mean?
Volkswagen first used the TDI term and continues to use it today. Audi also uses the term.
The first part of the TDI obviously stands for “turbocharged” indicating that the vehicle’s engine has a turbocharger.
The DI stands for Direct Injection. This is the most efficient way of getting fuel into the car’s cylinders.
Traditionally, both petrol and diesel engines used indirect injection where fuel was injected outside the cylinder, a system that was a hangover from when cars used carburettors.
There are other diesel engine names outside of the Volkswagen Group that often use the letter “d”, which means a car is diesel-powered. For example the BMW, Jaguar, Land Rover, Mini, Toyota and Volvo diesel vehicles all have the letter applied at the beginning or end of the trim designation.
Other manufacturers include the letter “C” to reference the use of common-rail injection. This is a system that allows high injector pressure for efficiency.
Hyundai and Kia call their diesels CRDi Mercedes-Benz uses CDI, while Renault and Nissan use dCi.
