Quote:
Originally Posted by extrashaky
During engine braking the computer cuts the fuel supply. When just idling (which is what happens when you're coasting in neutral) the computer has to feed fuel to the engine to keep it running. I have my doubts that it really saves you enough fuel to make any significant difference though.
That's not why some of us downshift. A performance car actually handles differently when it's in gear. When coasting out of gear, I don't feel like I have complete control of the car, nor am I or the car ready for unexpected situations that might require immediate maneuvering. Take your car to an empty parking lot and try slinging it around a bit in gear and then while coasting, and you'll feel the difference.
There are also some good arguments regarding the way gears wear that support engine braking. If you're always applying power to gear teeth from the same direction, they can wear unevenly. Engine braking evens out the wear pattern so that the teeth last longer and bite better, or so the argument goes.
|
I agree that the mpg difference between coasting in gear and in neutral is
insignificant. Tools might read about 300mpg for neutral and 9999mpg for in-gear, however, idling in neutral might only consume one gallon per
hour. And the time I spent coasting in neutral was not very much, only a few seconds before every stop. So maybe coasting in neutral might cost only $15 to $20 extra in gasoline for an entire year.
That's an interesting point you made about gear wear, I never knew about that. Some people believe that leaving the car in gear while coasting may slightly increase wear on the engine (instead of wearing on brake pads in neutral), which would make coasting in neutral a better choice. But the extra wear on the engine is probably next to nothing.