The RS 6's V10 engine produced at 6,250 to 6,700 rpm and of torque from 1,500 to 6,250 rpm, and more than BMW's 5.0L V10. , the RS6 was Audi's single most powerful car ever, and positioned the car ahead of its closest competitors, the BMW M5 and the Mercedes-Benz E63 AMG in terms of engine output, both of which have naturally aspirated engines. However the estimated price of the RS 6 sedan in 2010 was $160,000 USD (another source quotes $126,000 USD in 2009, making the RS 6 perhaps too expensive for the United States market) which set it apart from the performance variants of other executive cars: the MRSP of BMW M5's was $85,700 USD, of Mercedes-Benz E63 AMG's was $87,700 USD, and of Audi's own S6 was $78,025 USD.