Automatic know-how

Press, 6 August 1981, Page 20

Automatic know-how

If you are considering buying a fully automatic car, or have recently bought one, the following information should be useful: When starting a car with an automatic transmission, the automatic shift timing will be different depending on the accelerator pressure. If you are in a hurry to be off, press the pedal strongly. The timing of shifts can be varied by changing the force on the accelerator pedal. Unless the P position is selected when parking or the brakes are applied, cars with automatic transmission will move slightly, “creep,” even when the accelerator pedal is not pressed. When you want to accelerate, to overtake the car in front, for example, fully depress the accelerator

pedal. This will shift the automatic transmission down one gear so that faster acceleration is possible. At a specified speed, the transmission will automatically return to the higher gear. If the accelerator is kicked-down at too high an engine speed, the kick-down is automatically over-ridden. Unless the engine brake is used to help retard the car on long down-hill runs, the brakes tend to fade. In this case select the 2 or L position and the engine will act as a brake in the same way as in a car with a manual gearbox. With a manual transmission, if you change down while running at high speed, the engine may be forced to rotate to over-rev. The slippage allowed by the torque converter in an auto-

matic transmission helps reduce such shocks if the driver manually engages 2 or L at excessively high speeds. Consequently, automatic cars have a lower failure rate than cars with a manual transmission but some precautions must still be observed.

Since the torque converter has some inherent slip, the full output power is not transmitted even when the accelerator , is depressed rapidly and so accelerating too rapidly and too often only wastes fuel. Except in emergencies and when rapid acceleration is absolutely necessary, the accelerator should be used with discretion — this will reduce fuel consumption considerably. The automatic transmission is filled with torque

converter oil up to the specified level and this should be checked periodically — with the engine idling. The torque converter oil should be replaced every 40,000 km: observation of this rule will assure smooth operation of the automatic transmission.'

Always select P when leaving the car. If you are leaving the car with the engine still running, be sure to set the selector to P. It is not good practice to apply the parking brake with the selector in the D position.

Never select R while moving forward or D while moving backward. ■ Be sure that shifting to R and D is always done with the car at rest. To do otherwise, applies a considerable force to the torque converter.