A new high-performance Audi A3 has been spotted in testing at the Nurburgring. The RS3 is rumoured to use the engine from the upcoming TT-RS, a 2.5-litre 5-cylinder turbo engine that produces 340bhp and 450Nm of torque. As with all high-performance Audis the RS3 will put use the Quattro 4WD system.

With the engine coming from the TT-RS and the weight of the two cars thought to be roughly the same the performance specs should work out at pretty much the same. The TT-RS makes 62mph in 4.6sec and a top speed of 173mph. figures which would put the RS3 way above the Ford Focus RS and VW Golf R20.

With about 40bhp more than the RS, the Audi could become an alternative to the Mitsubishi Evo or Subaru Impreza. There’s always the chance though that the RS3’s performance might be slightly subdued so that the RS3 remains at the top of the hot hatch market without treading on the toes of the TT-RS.

With the new A3 not expected until 2010 it’s likely that we won’t see the RS3 until at least 2012 if we follow Audi’s recent release trends. Although nothing is confirmed the price may be around £35,000 at the time of release.