2004 Saab 9-3 Owner's Manual - Page 155

Starting and driving Lock-up The transmission's torque converter has a lock-up function. This can lock the torque converter in 3rd, 4th and 5th gears, thus reducing the engine speed and fuel consumption. 155 Driving in hilly country with a heavy load The transmission fluid can overheat when the gearbox is strained, for example, when driving with a trailer on hilly roads. To avoid the transmission fluid overheating, always drive with the selector lever in the D position. The adaptive gear change patterns are then active. High air temperatures or a faulty oil cooler can also cause the transmission fluid to overheat. Overheating reduces the service life of the fluid. Descending hills If the speed of the car increases while descending a steep hill, despite the accelerator being released, the control module will change down to 4th gear. If you desire more powerful engine braking, manually select a lower gear (see page 158). Kick-down When the accelerator is pressed down fully, a down change is made to optimize acceleration, e.g. for overtaking. Following this, the next higher gear will be selected at the optimum engine speed, unless you ease off the accelerator before reaching this. Kick-down works in manual mode in 4th and 5th gears if the engine speed is lower than 2,000 rpm. WARNING Remember to use the braking effect of the engine (1st, 2nd or 3rd gear) when you are descending long or steep hills to spare the brakes. Overheating can cause the brakes to fade! Towing Towing of cars with automatic transmission, see page 184.