downhill on gear fuel consumption

[Hammer]

is it normal that my h2 still consumes 47 mpg when going downhill on gear all my other cars dont consume fuel at all at the same situation ?

[The_Yeti]

Its a HUMMER Hammer, It consumes gas even when it's off.

Just kidding. I don't know, but I wouldn't be surprised if it did.

[Camou2]

The only way any engine cannot consume fuel going down a hill is to turn it off! Did you think they free spin or something?

[Olfart]

When I was a kid back in the 1940's I can remember riding from NY to Arkansas with my Dad. Since gas was rationed, he would cut off the engine at the top of every hill and coast down to the bottom.
Since your other cars didn't use gas going down hill maybe you shouod run the Hummer in reverse for a while. Maybe the tank will fill back up

[Hammer]

Originally Posted by Olfart

Hummer in reverse for a while. Maybe the tank will fill back up

now thats a good idea !

[Hammer]

I should have added is it normal ? my brand new z06 corvette does not or neither does my bmw m6 . btw my m6 gets worse mileage than my hummer

[Hammer]

Originally Posted by Camou2

The only way any engine cannot consume fuel going down a hill is to turn it off! Did you think they free spin or something?

haha but your wrong any modern engine when you coast in gear, you are using the momentum of the car to keep the motor spinning. Since the motor keeps spinning, and you arent giving it any throttle input, the injectors turn off. The ECU calculates that zero fuel is required to keep the motor from stalling.

Gravity is turning the engine.

[mbdougl]

If the injectors shut off wouldn't the engine stall?

[Hellz]

Originally Posted by Hammer

haha but your wrong any modern engine when you coast in gear, you are using the momentum of the car to keep the motor spinning. Since the motor keeps spinning, and you arent giving it any throttle input, the injectors turn off. The ECU calculates that zero fuel is required to keep the motor from stalling.

Gravity is turning the engine.

ill take what ever he is having..

more like when you coast, your engine goes to idle as if you were sitting at a stop light. its still on, and still consuming gas. this is where you are seeing the 47 mpg reading, because it is idleing. this is also how people can trick the MPG meter to read better MPG than what they are getting, but you would have to do this ALOT!

your momentum goign downhill is doing nothing to the engine.
your momentum going downhill is still turning your transmission, and transfer case. the tranny will shift gears depending on speed.

[Hammer]

Originally Posted by Hellz

ill take what ever he is having..

more like when you coast, your engine goes to idle as if you were sitting at a stop light. its still on, and still consuming gas. this is where you are seeing the 47 mpg reading, because it is idleing. this is also how people can trick the MPG meter to read better MPG than what they are getting, but you would have to do this ALOT!

your momentum goign downhill is doing nothing to the engine.
your momentum going downhill is still turning your transmission, transfer case. the tranny will shift gears depending on speed.

actually in my hummer I get better mpg when coasting on neutral so obviously what I said doesnt apply to all cars h2 for excample.

Many modern cars turn off all fuel when the accelerator is not depressed and the engine is turning over faster than idle. Some don't.

Even my old mitsubishi 3000gt vr-4 (600awhp) witch too have transfer case, transsmission and an all wheel drive when coasting downhill on gear I can see that injectors shuts down = IDC 0% and I dont burn much if any fuel at all ...