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6.7 with 6-speed automatic trans

Discussion in 'Ram Trucks' started by cp01, Jul 26, 2007.

  1. cp01

    cp01 Junior Member
    from ny
    Messages: 7

    What is the gas mileage everyone is getting with this engine and trans? Does anyone know if there are any changes between the 2007 and 2008 3500 with this engine and trans? I have a 2004 with 600-lb 325-hp motor and I'm only getting 17 mpg and I just ordered a new 2008 with above engine, so hoping for better mileage.
  2. KLC99

    KLC99 Senior Member
    Messages: 160

    I wouldn't expect to see better mileage with the new 6.7, or any of the new diesels from the big three. The new emissions systems cause them to use more fuel. 17mpg empty on the highway is probably doable, though, if you keep your speed down.

    If its not to late you may want t consider keeping the 04 or ordering one built before 1/1/07 as these models have the last of the 5.9's and are not choked by emissions equipment. (you won't get the new six speed, though, those are only available behind the 6.7
  3. Nascar24

    Nascar24 Senior Member
    Messages: 645


    I just picked up an 07 3500 Mega Cab with the 6.7L and 6 speed auto, I drove it from the dealer in Idaho to Massachusetts (nearly 3000 miles) I drove it at 75 mph and got 17.2 mpg brand new out of the box and not broken in. I towed my 30' 8300lb travel trailer on a 300 mile trip and got 9.2 mpg, again it's not broken again .Local driving has been around 13.5 mpg.

    I'm not surprised at the mileage, it's pretty close to what I was getting with my 01 PSD Excursion, so once it breaks in it should only improve.

    If you are looking for a good source for a great deal and a huge inventory to look through try Dave smith up in Kellogg, Idaho www.usautosales.com. They were great and they have more trucks than anyone else in the country! Who knows they may still have a 5.9L still available on one of their 19 storage lots.
  4. robmints

    robmints Junior Member
    from MD
    Messages: 17

    Did you look under the hood? I'm sure the tuning boys will come out with stuff that will make it a regular engine again, but it will be a good bit of change. If you think EGR and you think a little diaphragm doodad on the exhaust manifold piped into the intake you will have thought wrong. IMO if you expect better mileage with a 6.7 over your 04 5.9 your chances are slim and none, and Slim just left the building with Elvis.
  5. T-MAN

    T-MAN PlowSite.com Addict
    Messages: 1,363

    I would suggest just getting a chip for the truck, it will fool your overhead (and you) into numbers like 21 mpg or even 24 mpg. Heck my overhead now without the chip still says 19mpg. The Quad Zilla was fun but I worried about warranty work so I removed it. My mileage didnt change at all, except on the overhead. My buddy with an 06 has the edge, same thing no improvement. Seems like the guys who dont lie (and actually hand calculate mileage) all get about the same, right around 15 to 16 on all the trucks.
    Honestly I have yet to meet any one who hand calculates there mileage getting better then 18 mpg on the highway. That includes all the newer Ford Gm and Dodge guys. I here alot of Ford clowns touting 20 mpg all day long, BS ! Lets see your numbers. Oh I dont have them with me. So how do you know you get 20 mpg all day long ??? They usually fess up and say th eoverhead. Every tank I fill up I write down mileage.
    My 05 Ram gets 15.6 consistently on a mix. I could probally get 20 mpg if I set the cruise at 63 mph on a flat road with a tail wind.
    The overhead is an estimate guys not actual mileage.
    The BS of 20 mpg diesel pickups is a farce, some early 94 96 Dodges could it, and 2 wheelers with 3.55's could too. Any one else, just show me your numbers.
  6. BOSS550

    BOSS550 Senior Member
    Messages: 212

    06 F550, 6.0 PSD 7.9 MPG Actual never empty or trailerless
    02 2500HD Duramax 25.6 Actual Empty
    16.4 Actual towing

    I file mine for IFTA so these are handwritten
  7. T-MAN

    T-MAN PlowSite.com Addict
    Messages: 1,363

    The 02 is a Duramax in what a Geo chassis ?

    Every Ford guy I know claims 20 plus, my friend has a fleet of 6.0's and a couple 7.3's they average around 15 hand calculated no trailer or heavy hauling.
    Every now and again you here guys who claim 25 mpg with a diesel, I could see it with a 2 speed axle, manual or no hubs, air intake, larger exhaust, and a pre -emmisions mid 90's truck. I dont believe it can be done with a stock truck let alone a 4x4. Maybe the Duramax is pulling those numbers BUT that is the very, very rare exception.Definately not the norm.
  8. BOSS550

    BOSS550 Senior Member
    Messages: 212

    1) Most guys run Allison Autos behind a Duramax. Autos are not the hot ticket for fuel mileage. I have a 6 spd manual.
    2) The truck is stock.
    3) It is 4X4.
    4) It has 96,000 miles on it.
    5) It has 3.73 gears factory. I don't believe most other trucks have those.

    That Ford weighs 9300# empty and I usually pull at least 18,000 pounds of trailer plus whatever is on the flatbed. My GCW is usually no less than 28,000#. I doubt most of your Ford buddies ever see that kind of weight on a heavy day. That may be why mine has lower mileage than the rest. Hope this clears up some of your questions:waving:
    Last edited by a moderator: Aug 5, 2007