Despite looking exactly like a standard S3, according to our reliable sources that this test mule has new RS modifications underneath. Major difference between the two versions is the engine. While the S3 has a 2.0L turbocharged with 262 hp, the RS3 presents the new 2.5L 5-cylinder turbo into the A3 line-up. This new engine is actually borrowed from the TT RS, so it packs 340 hp and 331 lb-ft of torque. Therefore, 0-60 mph should be less than 5 seconds, and top speed without the electronic limited is around 170 mph. So this would easily tackle the 300 hp Ford Focus RS. In fact, with that atomic power, the RS3 may even compete with ultra high performance like a BMW M3 even.
Power delivery in the RS3 is set more rearwards from the S3. Where's Quattro all-wheel drive in the S3 has 50-50 torque split, the RS3 should have the new 40-60 torque spilt like newer Audis from the TT RS and R8 supercar.
Expect to see the all-new RS3 in beginning of 2010, with more aggressive cosmetic body kit, and a re-tuned exhaust.