Can an AT Transmission Coast in Neutral?
2 Answers
An AT transmission should not coast in neutral. The functions of a transmission are: 1. To change the gear ratio, as different driving conditions require different levels of traction; 2. To enable the vehicle to move in reverse; 3. To interrupt power transmission, allowing the engine to idle during startup, gear shifting, or parking, thereby cutting off power to the drive wheels; 4. To enable neutral gear, stopping power output when the clutch is engaged. Maintenance methods for automatic transmissions include: 1. Checking the automatic transmission fluid by testing its viscosity with fingers and replacing it if discolored or burnt; 2. Inspecting the manual shift mechanism, adjusting the linkage or cable connecting the shift lever to the manual valve to ensure the manual handle position matches the spring clip position inside the automatic transmission; 3. Adjusting the brake band.
I understand you're asking whether you can coast in neutral with an automatic transmission, but from a safety perspective, I strongly advise against it. Especially when going downhill, shifting to neutral disconnects the engine, preventing the transmission oil pump from circulating fluid properly. This causes the internal gears and bearings to grind dry, accelerating wear and potentially burning out components. Once, while driving on the highway, I tried coasting for a short distance, and the RPM started fluctuating wildly, causing severe jerking. Later, I ended up spending thousands on transmission repairs. Even more dangerously, it disables traction control, extends emergency braking distances, and increases the risk of losing control and colliding. Modern vehicles come with intelligent systems that balance fuel supply when coasting in Drive (D), making it more fuel-efficient and safer. If you really want to save fuel, using cruise control or manually downshifting is a much more reliable approach. Coasting in neutral is simply not worth the risk, especially for new drivers—never attempt it.
