Can it be done practically on any 2500? Theirs a guy that doesn't seem to be full of it that says he knows of 2WD 12v with taller then 3.55s, GV overdrives, and special tuning doing it (only minor- moderate mods). Running 1500-1800 rpms which would put the speed over 65mph with 3.55s even. I don't think it can be done with back up runs for prof without streamlining and weight reduction. Even if you drop the rpms a bit more and start lugging it. Then even the smallest head wind and your MPG would drop like a rock.

 

I'm calling BS on him. 30mpg is far fetched.

 

based on the 1st and 2nd gen 12v's that I've owned and a few I've maintained, no, that's hear-say. even a manual trans with a gear vendors would be nearly impractical to drive with higher than 3.55 gears. I'd believe a consistent 25mpg with a max effort 2wd mileage truck, it'd be difficult and take some seriously attentive driving technique but I don't think is impossible, especially with a rotary pump.

funny thing is my dad's '91 cab/chassis with 10k lbs of utility bed gets 17mpg while my flatbed '93 gets 17-20 slightly different throttle application...

it would be interesting to me to see a max effort 2wd, though. Lowered, small tires, minor engine mods, light weight synthetic gear oil...but at that point, I think I'd rather have a C10 or early 70's f100 with a 4bt and get 35mpg in a smooth riding bagged 2wd truck!

 

best i got with the 89 was 22 mpg. best i have got with the 97 was 26 mpg driving like a old lady on the highway at like 60 mph.

 

Ya I've known guys that have gotten mid 20s, but 30 is a long ways away. What about car conversion anyone know what they get? A damx was put into a buick @ ~5K and way more streamline IIRC it was hitting 30 mpg.

 

In Diesel Power a couple years ago there was a 2wd Reg Cab powerstroke that was getting like 32 mpg, but I haven't seen or heard of a CTD doing it.

 

He is referring to Crabbelle and the allegations are true. Here is his thread on another site.

33 mpg - Competition Diesel.Com - Bringing The BEST Together

 

I finally saw that it is possible, found these articles a few months ago when I got MPG crazy.

http://www.dieselpowermag.com/tech/g...ins/index.html

That's a 12V Cummins dually that gets 30mpg.

And this:

http://www.dieselpowermag.com/featur...age/index.html

That's a Powerstroke 7.3L F350 2WD that gets 26mpg.

Stock, the Duramax is one of the most efficient engines. I'm willing to bet if someone did mods similar to this in a Duramax or made a crazy tune with EFI live, 30mpg wouldn't be impossible to attain in a 2wd, especially with those tiny tires that GM uses.

 

**** i can get 25 mpg running between 70 and 75 mph in my 92. it is 2wd regular cab short bed and it has 3.55 gears. i think i could push 30 mpg it i slowed it down to about 60 or 65. but who cares about fuel milage its a truck. if you want gas milage buy a toyota car.

 

I think its doable...My girlfriends Dad had a 96 dually that got 26 mpg or better.