What Is Coasting?
The basic definition of coasting is driving with either your clutch fully down or your vehicle in neutral (not in gear), it happens when you put the clutch down unnecessarily or too early. Coasting causes your car to move without using any power and without your engine propelling. When you come off the gas the car begins to slow down gradually. This is called engine braking. If you depress the clutch immediately you will disconnect the clutch plate with the engine plate – therefore you will lose any potential engine braking. See the diagram to the right.
For example, imagine you are approaching a T-Junction downhill at 30mph. If you pressed the clutch down straight away, the car would most likely increase in speed as the vehicle would have no engine braking to help slow the vehicle down. It may feel like the car is free rolling.
Why Do Drivers Coast?
There are many occurrences in which your car will be forced to coast, in some cases this is on purpose, and others may occur without realising.
Many people believe that driving down a hill in neutral is beneficial because it saves fuel. Although technically you are not using any fuel, you are instead, putting yourself in immense danger.
Coasting can easily happen when turning corners or emerging from junctions as to do so; you are forced to change down to a lower gear quickly. Often, drivers do not give themselves enough time to both change gears and completely release the clutch before making a turn. This means it forces their car to turn the corner with the clutch down, therefore coasting. Immediately after changing gears, it is crucial to release your clutch slowly before changing over to a slight acceleration to turn.
Another typical situation where coasting may occur is when coming to a stop or while parking. It is common for drivers to put their clutch down too far in advance before becoming stationary. They may put their clutch down when approaching the parking space and then start to brake, only involve the clutch when you want to come to a solid stop.
Why Can Coasting Put Drivers In Danger?
If your vehicle is either in neutral or the clutch is down, it dramatically decreases the amount of control you have over your car. Although you can still steer, you cannot accelerate or brake as quickly in emergencies putting you in immense danger.
Coasting while driving forces your car to go into a state named ‘free-wheeling’. This means that the vehicle is not moving through use of the engine and is not in your control. As mentioned previously, coasting often occurs while turning a corner or emerging from a junction. If this happens, it will make it considerably harder to turn without going too wide; it will be tricky to make a tight corner safely, therefore ‘free-wheeling’. If there is traffic approaching on the opposite side of the road and you turn too wide, you could find yourself coasting onto the side of the road with ongoing traffic at speed.
Can Coasting Damage Your Car?
Rather than damage your car, coasting start to wear out internal parts quicker than they should. Coasting forces your car to drive with the engine disengaged, so rather than using the engine along with the help of the brake to slow down and stop, full reliance is on the brakes only. Eventually, your brakes will start to wear out and will need to be replaced immediately. You are likely to find yourself having to regularly replace both the brake pads and brake discs more than you need to.
Coasting During Your Driving Test
Although there is no set in stone law regarding coasting and it technically is not illegal, it is an issue that examiners will look out for in your practical driving test. All examiners test differently, some may be harsher revolving around the topic than others, so it is recommended to avoid any form of coasting on your test. Although they may not pick up on every time you coast, if it causes you to, for example, emerge from a junction too wide, this will result in a minor.
Coasting is not a topic that is regularly discussed during driving lessons, which is the main reason why many drivers are unaware of the dangers. However, your instructor would have completed full driving instructor training, so will have extensive knowledge on how to resolve the issue and give helpful advice to avoid coasting in the future. Don’t be worried to ask questions on topics that have not been previously discussed.