New Drivetrain Technology Developed by ZF
ZF, one of the world’s leading drivetrain component suppliers has recently developed two new devices that are destined to change the automotive world one car at a time.
8-Speed Automatic
Many of the world’s top luxury and performance brands rely on ZF’s 6HP26 6-speed automatic transmission, including the BMW 5, 6 and 7-Series, Audi A8 and S6, Bentley Continental, Jaguar XJ/XK, Maserati Quattroporte Automatica and many others. Since the launch of the gearbox in 2000, several other gearbox innovations have occurred including the introduction of the Borg-Warner-designed twin-clutch (DSG) gearbox, Mercedes-Benz’s 7GTronic automatic as well as the recent introduction of the Lexus 8-Speed automatic transmission.
With its new 8-speed gearbox, ZF has been able to cut back fuel consumption by roughly 6-percent on average over its own second-generation six-speed auto, without detracting from the shift quality or shift performance. Compared to a regular, run of the mill five-speed automatic, which many cars still utilize, ZF claims an average of 14-percent fuel reduction. What enables the engine to be more efficient is a new gear set and shift element, which reduce drag loss in operation. The gearbox was designed to be compatible with ZF’s future products, and has the capability to work without redesign for all-wheel drive and hybrid applications down the road. Finally, the icing on the cake is that it’s the same size as the 6-speed automatic, yet uses fewer components. The next-generation BMW 7-Series is expected to debut with the new ZF 8-speed automatic.
Torque Vectoring Differential
With so many auto manufacturers offering all-wheel drive on their vehicles, there has been a need to differentiate all-wheel drive systems with ones that are faster, lighter and more effective at power distribution. Some of the noteworthy advances we’ve seen in the past few years include the Haldex all-wheel drive system which uses friction-plate discs, employed in Audis and Volkswagens, Volvos, Fords and Saabs, or the Cardian shaft system found in BMW’s xDrive. The most revolutionary system, mind you, has been the Super-Handling all-wheel drive system of Honda/Acura, developed by Borg-Warner. Capable of torque vectoring, the system is capable of individually distributing power between the inner and outer rear wheels to reduce understeer and improve handling and stability characteristics in slippery conditions. Unlike any other system, it can reduce the power to the inside wheel during a corner, as well as speed the outside rear wheel up.
The new ZF system functions similarly to the Borg Warner system, but offers several improvements. It is capable of adding and reducing power to the wheels in conditions without throttle input, such as when cornering under zero throttle down hill thanks to a new planetary gearset. Unlike the version developed by Borg-Warner for Honda, this new torque-vectoring device can also be fitted to rear-wheel drive vehicles and can act as a limited slip differential reducing wear and tear on the car’s brakes. ZF has stated that it is partnering with BMW for the development of this differential, which we suspect may be an integral part of the next generation of xDrive.