allison trannies

[beanie]

anyone running a allison tranny behind a 8.1 gm dually 4x4 , whats the gas milage like ? , good or bad about um

beanie

 

[makemfat]

Mine's a '02 with the 8.1 and the 5 speed Allison. Passes anything but the gas station! Empty, not pulling a trailer, I get about 9 to 9.5mpg. Loaded, pulling either the flatbed loaded with hay, or the cattle trailer loaded, I don't even want to know! Of course the proper application of the right foot makes a big difference....and I know I don't do it any favors! I never figure to get great milage from a one ton. If I wanted milage, I'd get a Kia! Of course, the diesel guys have a different opinion, but I can actually work on this one, I can't a diesel.

 

[lavacarancher]

Don't think the Allison has a lot to do with your milage. Your poor milage is a result of 500 cubic inches running on gasoline and probably a heavy foot. I'm running an Allison behind a Duramin and get better milage than my wife's six cylinder Envoy. And that's comparing a 6600 pound vehicle against a 3000 pound Envoy.

You might get a little better milage with a standard transmission but top position in the Allison is lock-up so you don't have the loss in the convertor like the old automatics.

Good luck with your truck.

 

[Angus Cowman]

My brother had one and liked it he said he got between 8.5 and 10mpg loaded or empty