Results 1 to 5 of 5

Thread: What is average mpg for 6.2L V8?

  1. #1

    Question What is average mpg for 6.2L V8?

    I have a GMC Value Van 3500 and I would like to know what is the "normal" mpg?
    Based on the only trip I've taken in it so far, it was about 12mpg. But that was figuring that because the gauge read 1/2 full, it actually was.
    And does anyone know how much fuel the tank holds?
    I'm selling my van and I'm not planning on filling it up...half a tank was 50
    I appreciate the help.

  2. #2
    Join Date
    Sep 2001
    Location
    Concord, NC, USA
    Posts
    955

    Default

    Depends on lots of varibles such as transmission, gear ratio, weight of right foot. My Sub use to get 19ish but now gets about 17 with 700r4 trans, 4.10 gearing, 33" tires (just put on 35" so the jury is out on those). My Blazer will get 21 city/ 24 highway with 3.73 gearing 700 trans, 32" tires. 12 mpg seems low but I'm not sure what a "value van" is.
    Mark Chapman DP member #653;
    1983 K2500 6.2 Suburban, 4" lift, 35" tires, ATS turbo, Banks exhaust/intake, pyrometer, tachometer;
    1986 K5 6.2 Blazer, 2" lift, 33" tires, Banks intake, pyrometer, tachometer
    1963 wife, one owner, average mileage for the age but in excellent shape, a keeper
    1992 daughter, low mileage, pretty, limited edition, but requires some money to maintain
    1995 son, sports model, very fast & peppy, time will tell on durability and maintenance costs

    "Grease is good"

  3. #3
    Join Date
    Jan 2007
    Location
    Muskogee Oklahoma
    Posts
    29

    Default

    12 MPg does sound low but in my case very accurate. 1984 GMC C3500 Crewcab Dually. 6.2L Banks Turbo, SM465 4 speed with unsynchronized granny low and a 4.56 ratio rear end. I recently changed the rear end to a 3.55/3.54 (one or the other ). Haven't had much of an opportunity to check the mileage but it appears to be around 14 MPG now. Trying to save my bottle caps for a NV4500 5 speed with O/D. My RPM's showed 3200'ish at 65 MPH with the 4.56. Now it shows 2500'ish at 70 MPH.

  4. #4
    Join Date
    Jun 2006
    Location
    Texas
    Posts
    4

    Default Best MPG

    30 MPG, yes 30, its an 84 C-10, with 700R4, 2.70 rearend. Dual exhaust with glasspacks sounds like the old yellow cool bus runnin thru the hood.

    This is if I drive it like I have an egg under my right foot, if not and I drive like I stole it, then 20-22. One trip from Jacksonville NC to Houston I filled up in Atlanta just for kicks and rode all the way home without refueling speed was 70-75(dual 20gal tanks). Gotta love that 275 AC!

    p.s. tires arent stock size, they are +1 size bigger than 235s

    t rex 7

  5. #5
    Join Date
    Feb 2000
    Location
    Montana
    Posts
    11,557

    Default

    If the van has a newer 6.5 turbo engine, but you're running it NA, it'll produce less fuel economy than the original 6.2. The difference between 65-mph and 85-mph in a 3.42 geared 700R4 equipped pickup is about 7 mpg (24 vs 17).

    Jim

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •