For a model intended to sell partly on easy-to-understand functionality, the e-tron has a lot of driving modes to contend with: EV, Auto, Hold and Charge.
It defaults to the first and, as long as you stay shy of the kickdown or 80mph, will draw on the battery charge and electric motor exclusively, which it does well. There’s almost no whine, and while an electric-only 0-62mph time of 12.7sec isn’t up to VW e-Golf or BMW i3 standards, it feels snappy enough around town.
The intended natural state is Auto mode, in which the e-tron efficiently juggles its power sources. This generally manifests itself as electric motor only up to around 40mph, at which point the petrol engine kicks in, simultaneously supplying further drive and slyly recharging the battery. Lift off and the car decouples its transmission, allowing the A3 to coast to remarkably good effect.
In this setting, we managed 65.2mpg over 25 miles of A-road, B-road and town driving. The motor and engine blend to generally good effect with only modest throttle inputs.
There’s an inevitable delay between coasting, motor pick-up and internal combustion assistance, but it is tolerable – if a little inorganic. You can mitigate this by choosing when to switch between EV and Charge modes; the process demands some button pushing and is less efficient (49.8mpg over 25 miles) but does help to preserve battery life (largely by recouping power when it would otherwise be coasting).