AutosEngine braking: How to save fuel and protect your car's longevity

Engine braking: How to save fuel and protect your car's longevity

This technique is most often used with a manual transmission, although in an automatic one can use paddles.
This technique is most often used with a manual transmission, although in an automatic one can use paddles.
Images source: © phot. marcin łobodziński
Mateusz LubczańskiAleksander Ruciński

27 August 2024 17:11

Everyone knows that the brake is used to slow down a vehicle. However, more experienced drivers should be aware of the engine braking technique. Not only does it save fuel, but it also reduces the wear of car parts when used correctly.

Engine braking is straightforward but requires some practice and a good feel for the vehicle. Simply take your foot off the accelerator while a gear is engaged. An essential rule: the lower the gear, the more the car slows down.

So, for example, when descending a hill, shifting from fifth to fourth gear will help reduce speed. Shifting to third gear will decelerate you even faster, but you should watch out for excessive engine revolutions, leading to high repair costs. Therefore, it is worth getting to know your car—each model has different gear ratios. The key is to match the speed to the gear and the slope of the road.

In modern cars, fuel is not supplied to the cylinders during engine braking, which means we drive "for free." The exception is older vehicles with carburettors, where fuel is still delivered, making the saving zero. This might be discouraging for older drivers.

This technique is advantageous because it reduces brake pad wear. It is particularly useful in the mountains, where the braking system can overheat during long descents, depending on its condition and efficiency.

However, it should be remembered that improper use of this technique can be harmful. Sudden engine braking, for instance, shifting down two or more gears, causes the clutch to be heavily loaded, leading to faster wear. Such actions also negatively affect the dual-mass flywheel, designed to reduce vibrations.

Another issue is safety, especially in rear-wheel-drive cars. Although most new vehicles have an ESP system that stabilises the rear axle, it is still worth being cautious. Shifting down from a high gear on a wet or slippery surface can cause a rear axle skid. Electronics help, but common sense and physics are entirely different matters that cannot be ignored.

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