The all-electric Audi e-tron is already confirmed for production by 2012, possibly named the R4, but so far we've been in the dark on volume, but that's a detail that may have been filled in by the latest reports, which peg the number at just 1,000 cars. That's a very low number, but it fits with the highly exclusive purpose of the all-electric sports car, and is probably a fairly realistic representation of the demand for such a car.
A more accessible version could be on the way, however. A gasoline-powered version of an electric car is about as meaningless a concept as one could conceive, but that's just what Audi may have in store for us. Reports indicate the R4 could come in both in the zero-emissions EV form and as a gasoline-powered sports car to slot below the R8 in performance, though the electric will almost certainly be priced above the R8.
The idea of a gasoline-powered roadster or coupe fitting below the R8 but above the TT makes a lot of sense taken in the corporate context of the Volkswagen Bluesport and Porsche 914/356 revival rumors. And an all-electric sports car from Audi also makes some sense, at least in a "keeping up with the Joneses" sense, with Mercedes-Benz already at work on the electric version of the SLS AMG.
The electric Audi e-tron concept is expected to be brought to production life with a mid-mounted battery pack and four-wheel electric drivetrain, just like the show car. With such easily distributable weight, completely tunable traction and drive parameters and instant-on torque, the e-tron could prove to be a formidable car in any sense of the word, electric or not.
There's also talk of the R4 sharing a platform with the next-gen Boxster and Cayman, however, which makes little sense from a broader corporate perspective, especially for the conventionally-powered models. The same problem rears its head when it comes to powertrain selection within the Audi lineup.
A gasoline-powered version would need to crank out at least 300 horsepower to keep its pace above the Audi TT and TTS, though the 340-horsepower TT-RS would still likely outperform it, at least in acceleration tests. Applying that engine to a car significantly shorter and lighter than the existing R8--i.e., the rumored R4--could well pose problems at the other end of the lineup, necessitating a power bump to the R8 to keep sufficient space between models.
In all, the R4 might add a degree of accessibility to the Audi range, or fill a nice not currently occupied in terms of price and performance, but it will be a careful and difficult balancing act to build a car that's cheaper than the R8, faster than the TT, but not so fast it impinges on the R8's sales--all while sidestepping the Cayman and Boxster, themselves similar examples of careful model placement.
The end result, as well, is likely to be a somewhat crippled version of the car's ultimate potential, much like the Cayman and Boxster are often perceived to be intentionally restricted to keep their performance from brushing against the greatness of the 911.