The all-new BMW X5 will offer a new model and a first for the original Sports Activity Vehicle, the X5 sDrive35i, which marks the first time that an X5 model has been offered with rear-wheel drive. It, along with the X5 xDrive35i, will be powered by BMW's multi-award winning 3.0-liter TwinPower Turbo inline-six. The V8-powered X5 xDrive50i will use BMW's latest 4.4-liter TwinPower Turbo V8. It offers improvements in horsepower and torque, while at the same time improving efficiency. These models will arrive in US showrooms in the fourth quarter of 2013.