āeā for efficiency. The Audi efficiency models, namely the Audi A3 1.9 TDI e, Audi A4 1.9 TDI e and 2.0 TFSI e, are clean best-sellers. Even today, the Audi A3 1.9 TDI e undercuts the emission threshold aspired to by law. Its CO2 emission value is a mere 119 g/km. In the saloon and Avant variants, the A4 1.9 TDI e also combines high efficiency with powerful propulsion. The saloon version emits as little as 137 g CO2 / km with an average fuel consumption of 5.2 l of diesel. In spite of this, it generates 115 bhp and sprints in 11.2 seconds from 0 to 100 km/h.