
Audi has a fairly long history of hybrid innovation, starting almost 20 years ago with the 1989 concept release of the Audi Duo, also known as the Audi 100 Avant Duo, based off the already popular C3 100 Avant. The Duo, however, was one of the first vehicles to features the revolutionary gas/electric hybrid engine.
A succession of Duos evolved, eventually resulting in the 1997 production of the A4 Duo, the fourth generation of Audi’s gas/electric concept vehicles. Using a 1.9L turbocharged direct inject (TDI) engine and a 29hp electric motor, the car featured ...