The Foot Controls
The foot controls of vehicles are laid out in a similar fashion. The foot pedals of a manual vehicle, from right to left, are the accelerator (A), brake (B) and clutch (C), while vehicles with automatic or semi-automatic transmission have only an accelerator and brake pedal. When driving, you use the foot pedals to control your speed and power.
Accelerator or Gas Pedal
The accelerator or gas pedal positioned at the extreme right of the group of three pedals is operated by your right foot. The accelerator or gas pedal controls the rate at which the mixture of fuel and air is supplied to the engine.
When you press the accelerator, the more fuel goes to the engine, which turns to more power and the higher the engine speed. Releasing the accelerator or gas pedal reduces the power and will usually slow the car down (unless you are going downhill). When moving off from a stationary position, you need the right amount of gas. Too little gas stalls the car, whilst too much gas will make the vehicle surge forward. On the move, light and gentle use of the accelerator improves fuel economy and ensures smooth driving style, often referred to as ‘eco-driving’.
Like the accelerator, the footbrake positioned in the middle of the group of three pedals is operated with your right foot. This pedal operates brakes on all the wheels and is used to slow or stop the vehicle. It is operated by swivelling the right foot from the accelerator or gas pedal to the footbrake while trying to keep your heel on the floor. When applied, the footbrake also switches on the brake lights at the back of the vehicle, giving a warning to following traffic that you are slowing down or stopping. The more pressure you put on the footbrake, the more the vehicle will slow down.
When you start driving you will learn about ‘progressive braking’; this term refers to controlled use of the footbrake that enables a smooth reduction of speed and for safety. In normal circumstances, you should always press lightly on the brake pedal to begin with and gradually press harder as the brakes begin to act.
Clutch Pedal (Manual Vehicles)
The clutch pedal is operated with your left foot and on the left of the group of three pedals. The clutch is the connection between the engine and the gear box. When the clutch pedal is pressed down, it disconnects the engine from the driving wheels, which allows the car to stop without stalling the engine. Pressing the clutch pedal down also allows you to change gear.
The clutch consists of a pair of friction plates which are pulled apart when the clutch is pressed down. As you let the clutch pedal up, the two plates touch and power starts to be transmitted to the wheels. The point of engagement, when the two plates begin to make contact and the load on the engine increases, is known as the ‘biting point’. The further you release the clutch pedal, the more power is transmitted. Once the clutch pedal is fully released the clutch plates lock together and all the power from the engine is delivered to the wheels.
As soon as you have learned the basic skill of moving off and stopping you will learn about ‘clutch control’. This is a way of using the clutch pedal to make the car move very slowly and is an essential skill in many driving situations.
Using the Foot Controls in an Automatic Vehicle
When driving an automatic car, there is one less pedal to think about: there is no clutch pedal so the ABC of accelerator, brake, and clutch becomes instead simply accelerator (A) and brake (B). You should use the right foot to operate both of the pedals.
In next week’s article we shall be discussing the hand controls of a vehicle. We shall look at the position, function and use of the steering wheel, indicator switch, gear lever, and handbrake or parking brake. For further explanations or clarification on the articles in the Essential Skills of Driving column, consult the author.
Stephen K. Dieseruvwe
Director General, Delta State Traffic Management Authority (DESTMA)
**Driver Trainer and Road Safety Consultant