If that also includes MHEV then the statistics tell nothing. I bought a new Audi A6, it's a quite massive 3.0 diesel (210kW / 282 hp), I was actually surprised it's a hybrid when I went to register it and pay the "tax" - I got 50% off because it's a hybrid. I had to actually look it up on Google. It turns out most new Audi cars are MHEV, which is basically only used when the car is "coasting", the motor is decoupled from the rest and if you don't disable Start-Stop then it will also be turned off. Now in this special circumstance there is an additional battery + small electric motor that will only help to start the engine again. That's it. The motor doesn't really pull the vehicle. It does save some fuel especially on the highway, but not in the city. Audi mentions up to 0.7 liters / 100 kilometers for Audi Q8. I see it mainly as a benefit for the driver, in most EU countries you pay a lot money for bigger (more kW) cars.