In the clutches of automation

AT FIRST glance you think there is a pedal missing. Saab's Sensonic automatic transmission, which will soon be available on all models beginning with the 900 Turbo, features a standard looking gearshift lever, but further investigation reveals just two pedals.

In practice, it works like a manual gearbox, but instead of dipping a clutch, you lightly lift off the throttle and move the gear lever to wherever you want. Automatic clutches of this type are now used on many successful rally and Formula 1 Grand Prix cars.

The Saab Sensonic system eliminates the physical effort of operating the clutch and automatically co-ordinates the gearshifting parameters, except actually moving the lever, which most drivers claim is the most enjoyable part.

Smoothness and driving comfort are similar to those of a car with an automatic transmission, but with the added satisfaction of being in command.

An electric motor and hydraulic activator are mounted on the transmission housing to operate the clutch withdrawal lever under electronic control, relieving the driver of the need to use the left foot.

In dense traffic, such as in Hong Kong, it has been estimated the clutch pedal needs to be operated up to 50 times per kilometre. The driver can change gears more smoothly and much faster, improving performance and driving comfort.