Chevy 8.1 Vortec fuel mileage??
 

What kind of fuel mileage should I expect on an '01 8.1 Vortec 4X4 dually??? I've heard 5mpg towing 10,000 lbs and 8 with no load around town...

I have a 2001 GMC 2500 HD 4X4 Xcab with the 8.1 and Allison tranny..I get about 9MPG around town, much less when towing about 7500 lbs. I haven't calculated the mileage when towing because I don't think I want to know..:D

I just ordered a 2003 crew 4x4 with 8.1. 9 mpg around town huh? Better start saving gas money

I own an 01 crew cab dually with the 8.1. I've kept track of every tank of gas since I got it. It's a consistant 9.0-10.0 mpg truck. City 9.0 freeway 10.0. It gets even worse when you start towing. I tow a 35 fountain and she starts drink as soon as I hitch her up. I don't tow far so my milage is usually 8-9. I can only guess what it gets taking it for a long haul.

SR,

thanks for the info. What is your opinion of the truck overall? How is the ride(I'm coming from Jeep Grand Cherokee)? I assume this does not have the Allison and do you know what gears are in the rear? Thanks.

Sean

Sean, I highly reccomend a diesel. I will never go back to gas!

Great truck I wouldn't trade it for anything else. The ride is pretty good. Much better than the previous style dually. I've got the allison with the 4.10 gears and it's 4x4 also. I saw the 03's have the dvd player in them. that's the only reason i would want to trade it in. I have 32,000 miles on it in the last 24 months. No problems. A friend of mine has the same truck but has over 60,000 miles on his in the same time period and he trailers a boat all over the us and he's had no problems either.

I have the 8.1 in the 2500 Avalanche. I have seen as high as 14 at pure highway; not towing. I also have the 4spd M32 Auto with 4.10 gears. After the mods I have done, I think I get around 10 daily driving, and should still be above 7 towing. I hope!

I have a 2001 2500HD CC with 8.1, allison trans, and 3.73 gears. I get between 9.5 and 11.5 mpg. Only put about a 1000 miles on it since I bought it about 6 weeks ago and only towed with it once for about 50 miles. About 75% of the miles are at highway speeds for my mpg figures. This is about about 20% better than '93 454 TBI dually got with 4.10 gears.

Sorry for all of the questions...but, what is the difference between the Allison and a regular automatic transmission...is the Allison built better for towing?