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anyone have the 8.1L

Discussion in 'Chevy Trucks' started by AintNoFun, Feb 11, 2004.

  1. AintNoFun

    AintNoFun Senior Member
    Messages: 175

    im looking to purchase a new chevy 2500 hd. does anyone have the 8.1 litre engine? what kind of gas mileage do you get out of it? how does it plow, any complaints? thanks
  2. The Boss

    The Boss 2000 Club Member
    Messages: 2,099

    I used to have it. I had a 2001 2500HD. Nothing but problems with it so I traded it off. Great to plow with but the gas mileage was terrible.:gunsfiring: :waving:
  3. Hellbent.HD

    Hellbent.HD Member
    Messages: 34

    A friend of mine just traded his '02 GMC 2500HD with a 8.1 for a '04 GMC 2500HD with a 6.0,
    He didn't have any probs with the motor, but 3 transmissions in 29 thousand miles kinda ruined his outlook on the 8.1 due to the Allison that backed it.
    His truck was averaged 6-8 mpg, and i know that also had a little to do with it.
    He put a Western ultra mount on it not even 4 months ago, and said it plowed great for the little plowing he did with it.
    He even sold the plow off the '02..want's nothing to do with plowing i guess.

    The two biggest problems i've heard from people i know are these two issue's...
    poor milage and *some* of the Allison's have had problems..

    I would expect the 8.1 trucks not to get great milage. It's a heavy truck, run's 4.10's in the diff's, and is powered by a 496 big block..
    My 6.0 only gets a best of 10.5 mpg..

    Last edited: Feb 11, 2004
  4. BigRedBarn

    BigRedBarn Senior Member
    Messages: 133

    See another thread (HD Mileage) where I went into too, too much detail how I got 2.00 MPG with an 8100 in a 2500HD regular cab by plowing my driveways and nothing else. Obviously, this is an extreme case as the truck stays in the barn all winter except for plowing our driveways (I'm too lazy to take off the plow and the truck doesn't fit in my garage with the plow on as we have too, too much junk..., uh, oops, I'm going into too much detail again, aren't I?).

    In warm weather, without the plow and with typically 2 passengers, I get 10.5 MPG almost every tankful.

    That's with 4:10 gears. By the way, the 8-lug HD's have larger-diameter tires than the non-HD's, which means 3.42 gears in a non-HD are about the same as 3.73's in an HD; and 3.73 gears in a non-HD are about the same as 4.10's in an HD. Therefore, 4.10's aren't all that bad in an HD, if you see what I mean.

    If your gonna think about getting a 496 cubic inch big block, you can't really worry all that much about the mileage, right? But, it does seem like the people who frequent this forum believe that the 6000 and the 8100 get about the same mileage within 1-2 MPG's or so.

    Personally, I think gas mileage is highly dependant on the work being done by the engine. So, a bigger engine essentially does about the same amount of work as a smaller engine in getting a set weight moved down the road. It's in the wasted energy that a bigger engine uses more fuel. That can be from the bigger engine being heavier. And, it can be from the bigger engine using more fuel at idle and when coasting because it hauls in more air & fuel into the larger combustion chambers. OK, my engineering 101 discussion is done for today.

    Personally, this truck is great for plowing as you don't have to build up any momentium to plow; the truck just powers along without problem, almost like it's in low range.

    Finally, there's the "smile factor" from the big block. That is, there's the matter of the smile that's generated every time you feel that big-block grunt under your right foot. And, there're the smiles generated when you open the hood and people, especially those not familiar with these trucks, see "Vortec 8100" on the engine cover and they ask what that is in cubic inches and you tell them... "that's 496 cubic freakin' inches of Western-New-York-built big block." Ohhhhh, yeahhhhh...
  5. ratlover

    ratlover PlowSite.com Addict
    from IL
    Messages: 1,325

    Any reason you arnt looking into a diesel?

    I test drove a dualy reg cab 8.1......kinda fun to light up 4 tires :D

    I have *heard* that the 8.1 get supprisingly simmilar milage compared to the 6.0. I've drove some 6.0's and they are some running MFers too.....the 6.0 has way more power than needed to move snow IMO. If it is strictly for plowing and the diesel aint an option the 6.0 has more than enough grunt to get the job done(you will be limited by traction) and the 6.0 weighs less so you have more left over up front for a plow. If you are going to run a V box then you might notice a difference in power though between the 6.0 and the 8.1.....