The second generation Acura RL sedan, introduced in late 2004 as a 2005 model, was the first production implementation of SH-AWD. It is the most mechanically complex, and probably the heaviest implementation of SH-AWD. The RL is powered by either a 3.5L 290 hp VTEC variable valve timing and lift V-6 (2005–2008) or a 3.7L 300 hp VTEC V-6 (2009–2010) transverse mounted in the manner of a typical Honda front-wheel-drive car. In fact, the RL uses a highly modified version of the Honda Global Midsize platform, versions of which exist for the Honda Accord, Acura TSX and Acura TL. However, the front transaxle is directly coupled to a torque transfer unit. Two identical clutch/planetary gearsets power each rear wheel. The rear wheels are always overdriven with respect to the speed of the front wheels. The Acceleration Device can variably overdrive the rear wheel speed up to 5.7%.