3 ms·

I want to know more about why automatics can't do this, but Wikipedia only has an unsourced claim that "gliding vehicles equipped with torque converter-based au

by heftig 6y ago

I want to know more about why automatics can't do this, but Wikipedia only has an unsourced claim that "gliding vehicles equipped with torque converter-based automatic transmissions [causes] damage due lack of lubrication." If you release the accelerator, does it decouple the engine from the wheels?

rascul 6y ago
Gliding refers to shutting off the engine with the car moving, which isn't the same thing as engine braking (using the retarding forces of a running engine to slow the car down). Without the engine running there are various pumps that aren't running and fluid movement that isn't taking place anymore, so certain things won't be getting the proper lubrication while the parts are moving. https://en.wikipedia.org/wiki/Gliding_(vehicle) https://en.wikipedia.org/wiki/Gliding_(vehicle) https://en.wikipedia.org/wiki/Engine_braking https://en.wikipedia.org/wiki/Engine_braking
koonsolo 6y ago
I would guess it's technically possible, but probably not worth the effort.
kube-system 6y ago
Automatics can engine brake -- but in response to the person above who couldn't do it -- they typically do not exhibit that behavior in the default drive gear for fuel economy. (although some torque-converter automatics with inclination sensors will automatically engine brake on downhill grades) Most torque-converter automatic transmission also have selectors for holding particular gears to allow the operator to command engine braking behavior. As the other person mentioned, the quote you are citing means that you shouldn't spin the wheels of an automatic while the engine is not spinning. The input shaft of an automatic transmission typically drives the transmission's lubrication pump. If you spin the output shaft of a transmission of this design without spinning the input shaft, you are rotating the mechanism without lubrication.
mullingitover 6y ago
I have a Civic with a CVT, and it engine brakes if I'm going downhill and I tap the brakes.

by heftig 6y ago

rascul 6y ago

Gliding refers to shutting off the engine with the car moving, which isn't the same thing as engine braking (using the retarding forces of a running engine to slow the car down). Without the engine running there are various pumps that aren't running and fluid movement that isn't taking place anymore, so certain things won't be getting the proper lubrication while the parts are moving. https://en.wikipedia.org/wiki/Gliding_(vehicle) https://en.wikipedia.org/wiki/Gliding_(vehicle) https://en.wikipedia.org/wiki/Engine_braking https://en.wikipedia.org/wiki/Engine_braking

koonsolo 6y ago

I would guess it's technically possible, but probably not worth the effort.

kube-system 6y ago

Automatics can engine brake -- but in response to the person above who couldn't do it -- they typically do not exhibit that behavior in the default drive gear for fuel economy. (although some torque-converter automatics with inclination sensors will automatically engine brake on downhill grades) Most torque-converter automatic transmission also have selectors for holding particular gears to allow the operator to command engine braking behavior. As the other person mentioned, the quote you are citing means that you shouldn't spin the wheels of an automatic while the engine is not spinning. The input shaft of an automatic transmission typically drives the transmission's lubrication pump. If you spin the output shaft of a transmission of this design without spinning the input shaft, you are rotating the mechanism without lubrication.

mullingitover 6y ago

I have a Civic with a CVT, and it engine brakes if I'm going downhill and I tap the brakes.