ZF Develops 9-Speed Auto Transmission For Improved Efficiency

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You probably started driving in a car with three, four, maybe five speeds to choose between.

Manual transmissions led the way for a while with gears--five and six became commonplace, while the average auto might only have had four gears. Since then, an increasing quest for efficiency has seen that number double--or more.

At next week's Geneva Motor Show, Land Rover and transmission company ZF will demonstrate the world's first nine-speed automatic transmission in a production car.

Designed for transverse applications, such as the LR2 and Evoque, the 9-speed auto will replace the current six-speed found in the company's smaller vehicles.

Far from being needless frivolity, an a pure excess of gears, the new nine-speed has some real practical applications--chief among which is increased efficiency.

The extra gears mean an engine can stay in its most efficient operating range more of the time--neither laboring at low revs in higher gears, nor screaming away at higher revs in low gears.

At the same time, it allows engineers to tailor the transmission to a car's needs.

In the case of a vehicle like the LR2, that means a lower ratio first gear than the existing six-speed, enhancing the car's towing and off-road abilities. At the same time, a higher top gear reduces engine revolutions at higher speeds, improving economy and reducing noise. A skip-shift function allows the gearbox to downshift quickly for rapid acceleration.

The new unit is only a little larger yet 16.5 pounds lighter than the current transmission. It will be produced at ZF's Gray Court plant in South Carolina.

Further details and economy figures should be expected at or soon after the Geneva Motor Show--but expect improvements on the Range Rover Evoque's 28 mpg highway figure, and the LR2's existing 24 mpg highway rating.

Now, if we could just convince Land Rover to bring its 2.2-liter diesel engine over from Europe to pair with the new 9-speed...

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