I totally agree with this. One time i filled up at Quick Trip and got 260 miles to a tank. I average 240 or so with my 33's and 3:55's. It's all in the driver too, not gassing it hard off the line and letting off down hills. Also it seems like if I go faster then about 65 on the highway, my mpg dies. Then again our trucks speedo's are geared for donuts so the odometer is off anyways at 60 mph.

 

I'm happy if I'm getting over 14.5 mpg. That's what I've gotten since it was new except when the plenum was blown and it was in bad need of a tuneup. And another exception--when I'm towing my boat, I was getting 6 mpg.
My friend has a 1 ton 4x4 Diesel (Gen 4) and he gets 20 mpg.

 

My truck turns 2200 RPM @ 70 MPH W/ 4:10's

 

Dude i wouldn't say 14.5 - 15.5 is GOOD, but average. That's around what i get...i'm guessing, the only way i have any idea of what gas mileage i get is because i watched a review on youtube, from Motortrend of the exact truck i have, and they said 14 average in mixed driving.... so i say that's what i get.

 

rather then open another thread i figured to just add to this one.my '96 ram,318.4wd auto keeps getting better mileage.i just filled up,107 litres for 800km of driving most of it highway and the box fully loaded.according to my math thats roughly 22 mpg(math is not my strong suit though lol) my old truck is almost ready to roll up on 250,000 km.

does anyone else here get those numbers?

cheers.

 

I get 21-22 highway with my '97 1500 extended cab, 5.2, 5 speed with 3.21 gear. I ordered it from the factory that way so i could get the best mileage!

 

I followed the sure cure instructions for the sonnex kit, replaced my governor pressure solenoid and transducer, I dropped the valve body obviously and was able to adjust the bands by feel. I serviced the O/D unit and replaced a fractured snap ring as well as replaced iffy clutches. I did my plenum fix a long time ago, and the kegger mod but I cut DEEP into the runners, almost but not quite flush and i dished out the runner on the inside of the track. My heads were replaced before I bought the truck due to a factory defect. I installed harland sharp roller rockers and I do not have the death flash. I am running 4.56 gears, 37s 7 inch lift, full skid plates, 250 lbs worth of tool box and I am not an easy driver. Oh and I run full synthetic fluids as well.

Generally speaking I average 13 mpg mixed driving. I think my recent transmission freshening greatly increased my mileage from 10mpg to the above.

I did an experiment (sort of) recently when I broke an axle in the front...funny the axle broke not the stub shaft. Anyways, I took out the axles to get it home, and the pieces, and slipped just the stub shafts back in to support the bearings. Unfortunately I noticed no change in mileage and I monitored it closely. Oh well, I really wanted to get the hub conversion kit, now I'll just wait until my bearings are gone.

 

Id love to tell you what mine gets, but its not on the road yet, I can tell you what my Subaru gets though...

City 22 mpg
Highway 22 mpg
Long trips, 26 mpg at 80mph.

2.5L Boxer, Turbo charged 350hp/380tq @ 20lbs boost.

If I'm "Playing" about 16mpg

 

Yeah - I'll trade you mileage. I have gotten right around 12 since day 1......

 

actually common sense would dictate- since running 35" tires with 4.56 gears would be the closedest to stock ratios and engine/tranny load that 4.56 gears would have the best all around efficiency as far as power vs gas mileage...
if you drive like old man and dont mind sluggish truck 4.10 and even 3.55 would net better gas mileage depending on whether you live in a flat area or haul a lot of weight...but then why do you have a heavy full sized truck?