IMPREZA models are available with either a five-speed manual transmission or optional electronically controlled, intelligent four-speed automatic with a gate-type selector. Subaru claims changes to the transfer gear bearings have reduced noise in the manual transmission. The clutch pedal stroke is now shorter than ever and the leverage ratios altered to improve clutch action. The automatic transmission is 7kg lighter and 33mm shorter than the previous model. Fuel consumption with the automatic is claimed to have improved with the torque converter lock-up clutch now engaged at a lower speed. The auto driver can select between normal or power modes "manual" selection can also be made when the "hold" switch is turned on and the shift lever is moved through four range positions. In the manual transmission, a viscous coupled limited slip differential is used to constantly transmit engine power to all four wheels - during straight line driving the torque is split 50/50 front to rear. Automatic versions use a computer-controlled active torque split system that constantly monitors the driving conditions and distributes torque accordingly between a 95/5 and 60/40 ratio front to rear.