A 100 Year Old Idea Gets Into Gear

A CONCEPT FOR AUTO transmissions that dates back to 1899 looks as if it will finally reach widespread use. London-based British Technology Group is licensing Torotrak, a so-called infinitely variable transmission, to a growing number of carmakers, including Ford and Toyota.

Torotrak is a step beyond "continuously variable transmissions," such as those from Honda Motor and Van Doorne's Transmissie of the Netherlands. The Van Doorne version is used by Ford, Fiat, Rover, and Nissan. Continuously variable transmissions use adjustable pulleys to alter the ratio between the turning of the engine shaft and the turning of the car wheels.

In contrast, Torotrak uses pairs of disks with curved tracks, one connected to the engine and one to the drive axle. The disks are separated by three rollers. The rollers tilt between disks to change gears. Torotrak has fewer parts than a continuously variable transmission and doesn't require a clutch. It uses 15% less fuel than a manual gearbox.

Ford could be the first auto manufacturer to use the Torotrak transmission. It is considering putting it in its midsize Mondeo world car by the turn of the century.

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