Rumors suggest 740 hp from a twin-turbo V6, beating BMW’s hybrid V8 M5. The last time we saw Audi’s next-generation RS6 Avant, it was stuffed rather unceremoniously into a Nürburgring barrier. Related: Audi Is Eyeing More Wagons For America Beyond The RS6 AvantEarlier speculation suggested the RS6 could borrow the Bentley Continental GT Speed’s plug-in hybrid 4.0-liter twin-turbo V8. But other rumors contradict that theory, claiming Audi has instead chosen a twin-turbo V6 hybrid setup. Back in May, an RS6 prototype understeered into a barrier during Nürburgring testing.