Audi won't introduce a hybrid RS model until battery technology improves, the boss of its Quattro division has told Top Gear.

Speaking at the launch of the new RS3, Quattro GmbH chief Stephan Reil revealed that, though the firm responsible for Audi's hot models has investigated the possibility of a petrol-electric RS variant, the disadvantages of the added mass currently outweigh the benefits.

"We know that it [hybridisation] could give us more in terms of straight line performance," Reil told us. "But it is not just about straight-line performance. It is about performance in the bends, how it feels as well. At the moment there are more negatives than positives."

Though McLaren, Porsche and Ferrari have all embraced hybrid tech in the name of performance, Reil believes traditional petrol power is still currently the best fit for RS models.

But he admitted that, as battery technology develops and weight reduces, the dawn of the hybrid RS era is likely. "The next generation [of batteries] will be very interesting," Reil said. "They are getting smaller and lighter. We don't rule it out..."

Though it had been widely rumoured that the second-generation R8 - due to land this year - could be offered in hybrid form, it now looks like a potential petrol-electric version of the mid-engined two-seater could be some way off.

But as and when it arrives, a hybrid R8 is unlikely to be the only fast Audi to move away from traditional petrol power. Audi has previously hinted to TG that a diesel R8 could be in the pipeline, while the stonking RS5 TDI concept demonstrated Ingolstadt wants to translate its Le Mans diesel expertise to the road.

So: a petrol-electric R8? A diesel R8? Even an all-electric R8? Which would float your alt-propulsion boat?