What are the hazards of using engine braking?

[MacKing]

Here are the hazards of using engine braking: 1. It can easily cause damage to the engine mounts and engine cushions. At high speeds, frequently switching between aggressive acceleration and deceleration through engine braking will generate significant torsional forces on the engine itself. These forces are produced by the rotational acceleration of the crankshaft connecting rod mechanism and ultimately act on the engine support brackets and cushions. Repeated severe stress can easily lead to loosening of the brackets and aging of the engine cushions. 2. It can easily cause traffic accidents. Engine braking refers to lifting the accelerator pedal without depressing the clutch, using the compression resistance, internal friction, and intake/exhaust resistance generated by the engine's compression stroke to create a braking effect on the drive wheels. During engine braking, the brake lights do not illuminate, which fails to alert following vehicles and can easily lead to accidents.

[MacFelix]

I like to use engine braking to slow down while driving, especially on long downhill slopes to save brake pads. But it does have some drawbacks. Mainly, high-speed engine idling increases internal pressure, causing faster wear on components like piston rings and bearings. Frequent operation can also lead to engine overheating. If the cooling system isn't strong enough, it may damage cylinder walls or seals. In the long run, this shortens engine life and increases maintenance costs. Additionally, using this technique in congested urban traffic actually wastes fuel because higher RPMs consume more energy. I try to use it only when necessary on steep slopes and rely more on the brake pedal during normal driving. I recommend fellow drivers to regularly check engine oil and temperature to prevent minor issues from becoming major problems.

[McIsla]

From a safety perspective, engine braking sounds smart, but over-reliance on it carries risks. For example, during sudden downshifts, the vehicle may experience uneven deceleration, making the rear wheels prone to skidding or losing control, especially on slippery or curved roads. A sudden surge in engine RPM can shock the drivetrain, accelerating wear on the clutch or transmission gears. Under high load, it may also increase exhaust backpressure, damaging the catalytic converter. When driving, I gently combine it with foot braking to avoid relying solely on engine braking. Additionally, this technique isn't suitable for all vehicle types—some automatic transmissions may respond poorly, causing jerks that compromise ride comfort and smooth, safe operation. In short, moderation is key.

[MacKinsley]

Engine braking is not environmentally friendly, as those who care about ecology already know. During deceleration when the engine idles at high RPM, it emits more exhaust pollutants such as NOx and particulate matter. Fuel efficiency actually decreases because fuel injection is reduced while the engine load remains high. This may lead to clogged emission systems and premature aging of the catalytic converter. Although it can extend brake life, the drawbacks outweigh the benefits overall. It is recommended to combine it with conventional braking to reduce sole reliance on engine braking. Also, check the vehicle manual—many newer car designs have been optimized, so it's better to use it sparingly to protect the planet.