Quaife is a British company specializing in high-performance transmissions of all types. Most notably, they produce 5 and 6-speed manual transmissions for racing cars and motorcycles, and the Quaife ATB differential. Four-wheel drive systems and racing dogboxes are also among their produces.
Their famed ATB differential, related to the Torsen model, uses complex gearing to act as a sophisticated limited-slip differential. During wheelspin, an open differential transfers power via the path of least resistance to the wheel losing traction. The Quaife ATB differential, however, transfers power to the wheel which still has grip, pulling the vehicle out of wheelspin. This differential was fitted as original equipment on the Ford Focus RS, which has been described as one of the most track-capable FWD cars in Europe.