What is Engine Braking?
Engine braking is used to slow the vehicle down. The moment you come off the gas pedal you should notice the engine revs begin to lower gradually. Natural engine braking is safe, however, if you drop down a gear too early then you will notice a considerable amount of engine braking that it can become unsafe.
For example, if you are driving along at 50mph in 5th gear and then you suddenly drop down to 3rd gear for a big roundabout you will notice the car will almost pull back and slow down very suddenly. The dangers of this are you are slowing down suddenly without any use of the brake pedal which activates the brake lights and warns road users behind you that you are slowing down. Another danger of using the gears to slow you down more than necessary is your left hand is off the steering wheel much longer. If you are dropping the gears one by one, it often doesn’t come back onto the wheel. Two hands on the steering wheel is better than one when controlling the car round bends or approaching junctions.
What you should do
Natural engine braking is safe and effective. The best way to slow down for a big roundabout would be to come off the brake in good time on the approach and use the brake pedal gradually. This way you are using both types of braking – engine and brake pads. Once the vehicle has slowed down to 25-30mph then drop down into 3rd gear. You will notice when you bring the clutch back up the car continues to feel smooth and there is no sudden pulling back or roar in engine noise.
When would you use the gears for extra engine braking?
If you are driving down a very steep hill you may go down the gears earlier for extra engine braking. You must be wary of what’s behind you before doing this.
Excessive use of the brake pedal over a long period of time could lead to brake fade (brakes overheating). If you are driving an older vehicle brake fade is more likely to happen, so you may benefit from extra engine braking on steep downhills.
If your brake pads are badly worn or not working at all then although not ideal, engine braking may be required. Going down the gears earlier than normal will do this.
Driving in the snow and using engine braking
Too much use of the footbrake or heavy use in snow can increase the chances of skidding. With this is mind you may feel it is necessary to use the gears (engine braking) a little bit more to slow you down safely.
If you read the road ahead as early as possible and plan your approaches well, then the need for high amounts of engine braking is unnecessary.
Watch the video which goes through gear changing and the use of engine braking.