What is Transmission Braking?

[Barbara]

Braking, commonly known as 'braking,' refers to the action of stopping or reducing the speed of running locomotives, vehicles, other transportation tools, or machinery. The general principle of braking is to fix a wheel or disc on the high-speed shaft of the machine and install corresponding brake shoes, bands, or discs on the machine base, which generate braking torque under external force. Extension: Braking methods include hydraulic (car foot brake); mechanical (hand brake); pneumatic and vacuum-assisted pneumatic (truck foot brake); spring energy storage (large truck foot brake and hand brake); exhaust auxiliary braking (large diesel locomotives); engine idle auxiliary braking (operation); electromagnetic turbine retarder (large buses).

[GageFitz]

Engine braking is essentially using the car's engine to assist in slowing down, a technique familiar to manual transmission drivers. For instance, during long descents, constantly applying the brakes can lead to overheating and failure. In such cases, downshifting to increase engine RPM creates resistance that steadily reduces speed. Over my decade-plus of driving mountain roads, I've found this method far safer than relying solely on brakes. However, avoid abruptly shifting from high gear directly to first gear, as it can damage the engine. Automatic transmission vehicles also offer manual modes or low gears for similar effects. Modern electric vehicles are even smarter, automatically engaging energy regeneration for deceleration when lifting off the accelerator. While I've tested this and confirmed its energy efficiency, combining it with brakes remains essential for stability during rain or snow conditions.

[CassidyRose]

When it comes to transmission braking, I think the most ingenious feature in new energy vehicles is the kinetic energy recovery system. You can feel a noticeable drag when releasing the accelerator pedal, as the wheels drive the motor to generate electricity and store it back in the battery. I've calculated that it can extend the range by at least 5%. Especially in traffic jams, you don't need to frequently step on the brake, and the recovery intensity can be adjusted. Even in fuel-powered cars, you can use the technique of downshifting to decelerate. I'm used to anticipating road conditions in advance to operate. Although it's gentler than braking, you must be careful not to rely on it entirely. In case of sharp turns or emergencies, you still need to hit the brakes. Additionally, long-term use of transmission braking can indeed protect the brake pads. During car maintenance, I noticed significantly less wear.

[VonLuke]

From a mechanical perspective, transmission braking operates in two ways. In fuel-powered vehicles, downshifting increases engine speed, and the compression resistance within the cylinders during piston movement generates braking force. Electric vehicles, on the other hand, reverse the electric motor to function as a generator, converting the kinetic energy of the wheels into electrical energy. My gasoline car maintains a steady descent at 50km/h on long downhill slopes using third gear without needing to press the brakes. For electric vehicles, I often set the energy recovery level to medium, allowing for smooth deceleration when releasing the accelerator. Be cautious not to suddenly rev the engine too high, as it can cause rattling noises in gasoline cars. Essentially, transmission braking is an application of physical laws, and its energy conversion process is more efficient than friction braking, especially for electric vehicles where the recovered energy can be converted into additional driving range.

[JaxsonFitz]

Using engine braking wisely in daily driving can save a lot of trouble. When I drive my kids on mountain roads, I often use third gear to control speed, and my brake pads only need replacement every two years. It's even more noticeable with electric delivery vans - using strong regeneration mode for urban deliveries saves about a hundred yuan in electricity monthly. However, new drivers should pay attention to different scenarios: just use cruise control on highways, and manual downshifting is only necessary for steep slopes. On rainy slippery roads, combining engine braking with gentle pedal braking is safer. Here's a pro tip: when switching an automatic transmission to manual mode, shifting around 2500 RPM makes for the smoothest gear changes. Avoid sudden downshifts of more than two gears to prevent transmission damage.