BEST MPGs with W250 5speed

[jmd4993]

i have a 92 w250 5speed that i converted from auto. i was jw what guys are getting for mpgs. i go 21 all the time when mine was stock and auto. but ever since i touched the fuel screw it went down to 16 mpgs. i can't tell what I'm getting right now cause my odometer doesn't work right now.

[oldestof11]

My reg cab 4.10 truck with a DennyT2 and modded pump got an average of 18ish mpg. I had a best tank of 23 mpg going down and back to SOP. Highway I would get a consistent 21mpg.

[matthewh]

My dually, 4.10gears, 215/85/16 tires, 18-19 on freeway, as long as I keep it around 60, any faster, just pissing into the wind.
Around town, 16-17. I'm still stock, other than the lplp, pumps still a virgin

[jmd4993]

cause i have 3.54 gears, pumped turned (lost track of turns), stock fuel pin, let a buddy borrow my denny T2, Fass 150, 4"the, no air box, timing bump. my odometer is not working right now so i can't tell what I'm getting but last time i checked i was getting 16. that was before the getrag swap. then i had the denny T in and the pump was maxed , timing, exhaust, no air box. idk what the hell is up. but i guess i gotta actually see what I'm getting but I'm pretty sure it has increased.

thats awesome you guys are getting such good mileage with 4.10s thats more than i suspected. I'm wondering because I'm getting a flatbed and camper put on my truck and moving to montana for school so i want the best mileage i can get.

thanks for the info

[matthewh]

I do miss my 3.54 with the auto, could cruise at 75-80 comfortably and still pull down low 20's for mileage. Dually just built to tow

[93DodgeCummins]

I got the 3.54 gears with the Getrag. When it was stock, I was getting 18 in town and 20-26 on the highway going 65-70mph. Since rotated the pin and prob have 1-2 turns on power screw and put on 265 tires, I am getting like 16 in town and 19 on the highway. I think the tires are the problem but I dunno.

[cougar]

My 91.5 5 speed W250 with 3.07 gears seemed to be stuck on 18 winter/21 summer for ever. After changing to and dialing in my 7X.010 injectors, my mpg jumped to 24 summer.

[jmd4993]

its crazy how y'alls numbers are all over the place. I'm gonna be getting new nozzles made for my injectors prob like 5x12 sacs or i heard the marine inceptors are good. i just want an efficient tow rig cause I'm moving to montana for school and I'm putting a flatbed and camper on my truck. its just as soon as i touched the pump the mpgs went bye bye no matter what i did after turning the pump down and putting the stock pin in even the skinny ten ply tires i had on didn't make a difference. i think you just need to get free flowing injectors a good turbo and a tuned pump and thats what makes the difference it seems.

[CumminsPower59]

A good amount of why the numbers above are all different is because of individual driving styles, and darn near every truck is set up differently, at different altitudes and climates, running different blends of fuel. As long as you're getting decent mileage, you're good. Remember, these things are 6500lb bricks

[Nughuffer]

I've been seeing between 18-20mpg this winter with my 93 W250 5sp 3.54 with 285 75 16" Nitto TG's @60psi. I've rotated fuel pin, 1/8" timing bump, Bosch 190's and a fairly conservative power screw setting. It doesn't smoke at all even if you try and its fairly doggish and laggy until 2k rpm but mileage is steady. 2k is perfect hwy rpm @ 68-72mph and that's what 95% of my 75mi/day commute consists of. With summer fuel I can see 22mpg fairly easy and 24-25mpg if I draft the big rigs. That is if my hood stays latched....

[RCCUMMINS89]

My truck... one 37s, that has a fender well that is 49" off the ground and has a driveline angle of 38 degrees....weighing in at 6940 pounds (after the 80 install) still gets 20+ at the proper speeds. If I play a lot, I get 16mpg.

IMO it has to do with proper tuning more than anything else. I run a 62/68/.70 turbo and massive 5x17 sized injectors in a SAC design. Stock head, stock valve train and cam.