Commanding the Power: Accelerator, Steering and Brakes
Updated Dec. 31, 2020The pedals in the driver’s footwell are used to control the amount of power passed from the engine to the wheels. By managing this power, you can increase or decrease the speed of the car. When first setting yourself up in the driver’s seat of your new vehicle, make sure you can reach the pedals well enough to press them all the way down to the floor of the car.
If your legs are not long enough to reach, you may be able to move the driver’s seat forward using a manual lever under the front of the chair near your calves, or electronic controls to the side of the seat. If this is not possible, you should contact the vehicle manufacturer to see about getting adjustable foot pedals installed. Now, let’s find out more about those pedals and the other devices you will use to control the speed of the vehicle.
Accelerator
The long, rectangular pedal which sits farthest to the right is the accelerator (also referred to as the gas pedal, or throttle). This pedal controls the flow of fuel and air into the vehicle’s engine. As you apply pressure to the accelerator, more fuel is fed into the engine, increasing its power output. The energy produced by combusting fuel is transferred to the crankshaft, causing it to rotate faster as more pressure is applied to the throttle. The transmission – which we will discuss later – connects the crankshaft to the driveshaft, which rotates the wheels. Thus, depressing the accelerator causes the wheels to rotate faster, increasing the speed of the vehicle. Taking pressure off the accelerator will decrease the vehicle’s speed unless you are traveling down a steep enough hill for its speed to be maintained by gravity.
All vehicles respond to pressure on the gas pedal differently. You must get to know your car, to learn how much pressure to apply to the accelerator to reach the desired speed. If possible, practice controlling your speed in a safe place away from other traffic and obstacles, before taking your car out on the road.
Brake pedal
To the left of the accelerator is the square-shaped brake pedal (this is the service brake pedal which operates on a different system to the parking brake). Applying pressure to the brake pedal will press the brake discs or pads against the surface of the car’s rotating wheels, creating friction that will slow them down. Like the accelerator, the responsiveness of the brakes varies from vehicle to vehicle.
When learning to use your brakes effectively, you must first ascertain whether your car has conventional brakes or an anti-lock braking system (ABS). With conventional brakes, applying too much pressure to the brake pedal could cause your wheels to lock, making it impossible to stop or steer the car. To stop a vehicle with conventional brakes quickly, the driver must continually press and release, or “pump” the brake pedal. This will pulse the brakes against the wheels, slowing them down gradually without making them lock up.
Vehicles with anti-lock brakes must be handled differently during an emergency stop, which is why you need to know which braking system your car uses. In ABS-equipped vehicles, an electronic system manages the amount of pressure the brakes apply to the wheels, automatically easing off before the wheels begin to lock. To stop a car with ABS brakes during an emergency, press and hold the brake pedal in a single, firm motion – the car will do the rest.
Both the accelerator and the brake pedal must be operated with the ball of the right foot while keeping the heel on the floor of the vehicle. Keeping your left foot out of the way will make sure you do not accidentally press the gas pedal and the brake at the same time, which could seriously damage the car. Resting the right heel on the floor of the car will allow you to pivot your foot quickly and smoothly between both pedals as needed.
Clutch
Vehicles with a standard transmission have a clutch that connects the engine to the transmission. In these manual vehicles, a clutch pedal will be present to the left of the brake pedal. Pressing the clutch pedal down disconnects the engine from the transmission, effectively cutting power to the wheels. With the engine disengaged, the driver is free to shift the transmission into a different gear using the shift stick, which is usually located between the driver and front passenger seats. Drivers should reserve their left foot exclusively for operating the clutch pedal.
Dead pedal
The dead pedal is not so much a “pedal” as it is a raised footrest. Most vehicles feature a dead pedal to the farthest left side of the driver’s footwell, to serve as a place to rest your left foot while you drive. In automatic vehicles that do not have a clutch pedal, the driver’s left foot should remain on the dead pedal. Placing your foot on this platform will help you to maintain good posture while you’re driving. It will also give you a surface to brace yourself against if you need to turn or brake sharply.
Parking brake
All vehicles are built with a parking brake on a separate system to the service brakes. The parking brake (also known as the emergency brake) is usually situated between the driver and front passenger seats and is operated with the driver’s right hand. Whenever you pull off from a parked position, you will need to deactivate the parking brake by pressing a button on the lever and pushing it down. To engage the parking brake when you stop, pull the lever straight up.
The parking brake fixes the vehicle’s back wheels in place and is primarily designed to stop the car from moving when you are parked. However, it can be used to stop the car in an emergency, should your service brakes fail. Bear in mind that the parking brake will not be as effective as the service brakes in stopping the car, as it only works on the rear wheels.
Transmission
The explosive energy produced in your vehicle’s combustion engine is transferred to the wheels via the transmission. The transmission’s job is to manage the amount of power coming from the engine using different gears, then convert that power into torque (rotational force). If the engine’s crankshaft were connected directly to the wheels without a transmission to mediate the power, your wheels would rotate far too quickly, and you would have little to no control over your speed.
The gears in your vehicle’s transmission system range from low to high. In lower gears, the car can only travel at slow speeds but will have access to the engine power needed to pull off from a standstill, drive uphill or pull a heavy load. The higher up the gears you go, the wheels receive less raw power from the engine but can turn faster.
Transmission systems in modern vehicles are either manual or automatic. In a manual vehicle, the driver is responsible for selecting an appropriate gear for the driving task. In automatic cars, the vehicle does most of the work for you.
Automatic transmission
Most modern American vehicles have automatic transmissions. In automatic vehicles, a torque converter connects the engine to the transmission. The torque converter’s job is to detect changes in engine output as you increase speed by pressing the accelerator. It then shifts to a higher gear automatically, when it senses the vehicle requires it. Though the torque converter in these vehicles handles gear shifting, the driver is still responsible for selecting an engine “mode” using a lever inside the passenger compartment. This lever is usually found between the driver and front passenger seats, in front of the parking brake.
Automatic transmission positions
In an automatic vehicle, the driver will move the shift stick forward or backward to select one of several transmission modes, based on what they want to do with the car. It may be necessary to depress a button on the stick in order to move it. This safety feature has been implemented to stop drivers knocking the stick and shifting gears by accident.
Here are the main transmission positions in an automatic vehicle:
- 1
P (Park).
This position stops the wheels from rolling by locking the transmission. - 2
R (Reverse).
In reverse, the wheels will rotate backward. In many vehicles, selecting this position will also activate the reversing lights on the back of the car. - 3
N (Neutral).
This position disconnects the engine from the drive wheels. No power will reach the wheels, but they can still rotate. While in neutral, the vehicle can roll forward or backward. - 4
D (Drive).
This is the position you will use most often. It sets the car in forward drive mode, where gears are selected automatically as the speed of the vehicle changes.
Many modern automatic vehicles have additional stick shift positions beyond the four main modes listed above. These are included to let the driver take limited control over the transmission, in situations where they do not want the engine to automatically move up through the gears. Most automatics include one, two, or three restricted gear selection positions, which are labeled differently in different models of car.
- 1
“LOW”, “L”, “D1” or “L1”.
This position will stop the vehicle moving above first gear. Staying in first gear can give you more power when traveling up very steep inclines and help to maintain traction at low speeds on a slippery roadway. Selecting this gear can also help the vehicle decrease speed when traveling downhill, or at very low speeds. - 2
“D2” or “L2”.
This fixes the transmission in second gear. It will allow for better traction on slick surfaces and more power when climbing moderately steep hills but can be used at slightly higher speeds than first gear. - 3
“D4” or “Overdrive”.
This function is less common, though it does appear in many newer automatic cars. You can select this gear to improve engine efficiency when cruising at speeds in excess of 45 mph.
Manual transmission
Though less common in American vehicles, many European cars and older models of car have manual transmissions (also referred to as a standard transmission). In a manual transmission vehicle, a clutch connects the engine to the transmission. The driver must select gears manually using the stick shift next to the driver’s seat while depressing the clutch pedal to disconnect the engine from the transmission.
Driving a manual transmission vehicle is arguably harder than driving an automatic, as the driver must manage gear changes in addition to other driving-related tasks. However, many people prefer a manual transmission as it affords them more control over the vehicle’s behavior and performance. Opinions are divided over which type of transmission is safer. Some experts believe that automatics are safer as they put less strain on the driver, while others think that manuals are safer precisely because they require more hands-on engagement, which means drivers are less likely to become distracted or drowsy behind the wheel.
Manual transmission positions
When driving a manual transmission vehicle, you should move up through the gears as the car increases speed. If you need more power from the engine, move down a gear. Your vehicle owner’s handbook should be able to tell you the optimum speed ranges for each gear, though we will provide you with some general guidance. Here are the stick shift positions in a manual transmission vehicle:
- 1
N or Neutral.
When you start the engine, the gear stick should be in the neutral position. To put the vehicle in gear, you must fully depress the clutch pedal. After changing gear, ease off the clutch gently. - 2
1 or First Gear.
This gear is typically used for pulling off from a parked position (unless executing a downhill start, as gravity will get the car moving). First gear should only be selected when traveling at speeds of 0 -10 mph. - 3
2 or Second Gear.
Shift to second gear as the vehicle picks up speed. You can also pull off in second when starting downhill. Second gear should be selected when traveling at speeds of 10-20 mph. - 4
3 or Third Gear.
Third gear is primarily used as an intermediary gear to pick up speed before progressing to fourth gear. Third gear should be selected at speeds of 20-30 mph. - 5
4 or Fourth Gear.
Fourth gear should be used when driving in a moderate speed, low hazard environment. This gear is At anything over 40 mph, the vehicle should be set in fifth gear. This will preserve fuel and prolong the life of your engine. Usually, fifth gear will be selected when traveling on open, high-speed roads. - 6
R or Reverse.
This position is the same as the “R” mode in an automatic transmission vehicle. Selecting reverse allows the wheels to rotate backward at low speeds. You would shift to this position when backing up.
Some manual transmission cars have an additional “sixth gear”; this tends to be more common among diesel-powered vehicles. Sixth gear may be selected to increase fuel economy when cruising at high speeds.
Supplementary power options
Vehicles often have additional features to help drivers manage the amount of power reaching the wheels. These systems – such as four-wheel drive and cruise control – are designed to help the driver get the best performance from their vehicle in different driving environments.
Four-wheel drive
In four-wheel-drive vehicles, the engine can supply drive power to all four wheels simultaneously. This may be the way the vehicle operates all the time, or it may be an option that the driver can select if the situation demands it. Activating the four-wheel-drive feature (also known as 4WD and 4X4) greatly improves traction during hazardous conditions, such as when driving over snow, mud, uneven or rocky terrain, ice and any other situation in which maintaining control may be difficult.
Cruise control
Most modern cars have a cruise control feature which can be activated when driving for a prolonged period at a consistent speed. Cruise control will set the vehicle’s speed so that the driver can take their foot off the accelerator, though they will still have to operate the steering wheel. Being able to rest your foot makes for a more comfortable and convenient driving experience on long-distance journeys. Never activate your car’s cruise control feature when driving in moderate to heavy traffic, on a wet or icy road or during any situation which may warrant a sudden reduction in speed. Remember, you will need to deactivate the cruise control to regain full control of the car.
Getting used to a new car
Finding your way around a new car can be a daunting prospect, even for experienced drivers. As you will have a lot to think about while driving, it is important to familiarize yourself with the instrument panel and steering column controls before you take to the road. When you start learning to drive in your new vehicle, operating the pedals, steering, scanning for hazards and shifting gears will be mentally strenuous enough without having to search for other switches and levers. Though sooner than you think, performing these driving tasks will start to get a whole lot easier. By the time you are ready to sit your practical driving exam, you will be able to adjust your speed, turn, change gears and operate other in-car controls effortlessly and intuitively.
As you get to know your new vehicle, use the information in this module to support your learning. Be sure to spend time reading your vehicle owner’s manual too! It may contain important details about controls, maintenance and safety which are not covered here.