Engine performance

gasoline

#1

Does a gasoline engine consume more gasoline when a car is coasting downhill in gear or out of gear.


#2

with manual transmission:
It uses more gasoline to keep the engine running at idle, out of gear. When in gear, the drive train drives the engine, and the fuel is cut off (injectors).


#3

Fuel is also cut off automatic transmission when decel above about 1500 rpm.
On long downhill at idle, fuel injectors are periodically activated by PCM to maintain cat temp.


#4

Great information. Thanks for the help.