Which Audi model was the first to feature a TDI engine?

The Audi 100 was the first Audi model to feature a TDI engine.

Audi unveiled the 100 TDI at the 1989 Frankfurt Motor Show. Its 2.5-litre, five-cylinder diesel combined turbocharging with direct fuel injection and electronic engine management—an advanced arrangement for a passenger car at the time. Production versions followed for the C3-generation Audi 100, with the engine commonly listed as producing about 120 PS.

TDI stands for turbocharged direct injection. The technology helped diesel engines deliver strong low-speed torque while using fuel efficiently, helping make diesel passenger cars more attractive in Europe. The Audi 100’s streamlined body also suited the engine’s economy-focused character.

A common mix-up is confusing the Audi 100 with later TDI milestones. Audi subsequently introduced a V6 TDI in the A8 and expanded TDI availability across models such as the A4, A6 and Q7. Those cars helped popularize the badge, but they were not the first Audi models to use it.