Many people like to slide downhill in neutral because they think it can save fuel. For the old generation carburetor car, idling is indeed the most fuel-efficient state of the engine. For more and more EFI Motorcycles now, when coasting with gear, the driving computer will reduce the fuel injection quantity according to the speed of the vehicle. When the engine reaches a certain speed, the fuel will be cut off automatically, and the fuel consumption is lower than the idle fuel consumption, so this conclusion is not tenable at present.
Once you slide in neutral, it means that the two tires are spinning fast on the road alone. In this case, the traction of the tire will be reduced. A parallel problem: when braking, if the auxiliary brake of the engine is lost, the brake power will be greatly reduced, and the brake disc is very easy to overheat. When the rear brake is used to control the speed for a long time, the temperature of the rear rim is too high, which is easy to cause the abnormal wear and early damage of the rear rim bearing seat, causing the rear wheel swing and poor controllability; when the temperature of the rear rim is too high, it will also cause the high temperature failure of the friction plate, reduce the braking effect, and accelerate the wear of the friction plate and brake disc. The above situation not only increases the cost of maintenance and replacement, but also has a great potential safety hazard.