Electric ‘turbochargers’ are one of those why-didn’t-that-happen-before ideas we all expected to see first in sports cars.

After all, what motor most needs fine throttle response and the elimination of off-boost torque holes?

Well, Audi thinks diesel engines do. What’s more, it think diesels and electric ‘turbos’ fit together so well its demon spawn might replace the 4.2-litre V8 petrol motor in the RS5.

Audi RS5 TDI Concept rear

The RS5 TDI uses the bi-turbo 3.0-litre V6 TDI, plus an electric turbo that’s technically not a turbo. A turbocharger sticks out into the exhaust flow, which hurts it down below 3000rpm when there isn’t enough air going past.

An electric turbo doesn’t have that problem, and sits so far away from the hot bits that it doesn’t need an intercooler. The full picture adds a lithium-ion battery, a separate 48V electrical system and the 7kW electric whizzer. The package weighs 20kg all up and regenerates off the brake system.

Audi RS5 TDI Concept engine

That low-down grunt ends up translating to, as we found out after several side-by-side tests, the TDI concept being quicker than the RS6 Avant to about 60km/h. Easily. There’s no dialing up revs, no managing boost, it’s just stomp and go. Audi’s also cranked the artificial sound up to 11, so it’s deep and angry like an outrageously masculine, lower-revving RS6.

Audi RS5 TDI Concept driving
Audi RS5 TDI Concept interior

Petrol engines will always have a place, but if this is the almost-present then hi-po mainstream petrol power might be numbered.

Specs

Engine: 2967cc V6, DOHC, 24v, twin-turbo, electric compressor Power: 283kW @ 4200rpm Torque: 750Nm @ 1250rpm 0-100km/h: 4.0sec (claimed) Top Speed: 280km/h (claimed) Price: N/A