fuel mileage with what mods

[ellis93]

I'm curious as to what mileage you all get with the mods on your trucks. List your mods,axle ratio,and common rpm with best mileage.

My truck 5speed/4:10s
Stock running 70mph 20mpgs average
Now with mods in sig running 70 18mpgs with twice the nuts it had stock

[RCCUMMINS89]

Stock (stock tire size too) 16.5mpg

tuned pump, 1/8 bump w/spacer, stock injectors, wh1c and 37s - 22mpg

Now anywhere from 17-21mpg (dp and timing affects it allot)

[Deathrod]

91 non ic motor, stock stick, 1/8 bump, electric fan, a518, he351ve, 2.75 rear gears, 28" tall tires. Best I can get over a full tank is 33 mpg....oh ya...mostly due to the dodge delete!!!!,

[cmann250]

2wd, 727, 307s, non intercooled injectors

Stock with the exception of a rotated fuel pin- 20.8 over 10 gallons, mostly road farming. Likely a fluke.
Cummins piston pump, home made intake, turned up VE, still non-IC with stock H1C- I knocked down a bit over 20 for 4 or 5 tanks in a row. Mostly 70 mph which is a tad under 2400 RPM.

They're efficient mills. I wonder what the intercooler and HX35 did to mpgs.

[Tacoclaw]

'Rag, 3.07's, 265/75/16 AT's, twins with a terribly sealed exhaust side, 5x14's, bumped timing, maxed pump.

Pulled 19.5 on the interstate heading up north. Crappy, hilly, and doing 70 the whole way. Never checked it otherwise, my odometer has never worked.

[oldestof11]

Best: 23.xx mpg over a 500 mile trip to SOP. Route 1 way included highway for about 2 hours and 4ish hours of country highway through various towns.

Average 15 in winter and 18-20 in summer.

33x12.5 MT's, 4.10:1, RCLB, Getrag, timing to head, stock lift pump, injectors, and turbo, DennyT pin, homemade downpipe, injection pumped tuned, 4200rpm spring, electric fan

[cougar]

I'll stick to my 91 sense that is the one I've been working on.
When I got it some time in the late 90s it had:
370 marine injector nozzles on 1st gen bodies. (the old school way)
Timing bumped a tooth, but pump retarded about a 1/4".
Fuel screw to the collar.
Stock 91.5 H1C, stock size tires, 3.07 gears
Smoked something awful.
18-21mpg.
Mods sense then?
see signature below.
Still get 18-21mpg.
Doesn't smoke as bad, but can still cause a solar eclipse.
There were transitionary turbo mods in between, but still no change in fuel mileage.
I also drive like a little old man too, that's probably why.

[dazedandconfused]

93 cummins all stock except turned fuel pin and bottomed star wheel which was already done. Still running stock type lift pump with rebuilt 518 with unkown mileage. Running 3.55 gears and a 28" tire in my short bed, half ton it averages 21-23 running 70-80mph.

[Ram360man]

89 w250. Timing almost to the head with a 60 mm gds and 2.5 inch crossover. 727 with 3.07 gears and 245/75/16 tires. gets 16 in the summer and around 14 in the winter. Pump is maxed out and has horrific fuel line leaks. Would probably get 18 if I fixed them. Start better too.

[CumminsPower59]

The Big Red Pile...bone stock.

Non-IC, sloppy 727, 3.07's, 305/70 17 MT/R's ...best of 14.05 mpg (GPS/hand calculation)

[rockmike]

stock fuel pin before the W/M I ran the truck over to Seattle area and back about 700 mile round trip runnin 70-75 mph my truck got a consistant 26 MPG.

[apexfd]

My STOCK 91 non intercooled 2ws 5 speed is getting 28mpg on the highway and ~22-25 city depending on how I drive. Keep in mind in Canada 3.7854L = gallon.

[93 W350 LE]

93 W350 club cab dually automatic,4:10's, 235/85 16's, turned fuel pin, bottomed star wheel, stock pumps, injectors and timing. Mixed hiway and town driving to and from work avg15-16 mpg's. Soo jealous of all you guys getting 20+, but I guess 4x4 sucks some milage.


Eric

[Tacoclaw]

I think it's mostly just how low the 2wd's sit, it's pretty obvious our engines aren't that thrown off by weight. What's an extra 1k lbs in axle and transfer case to our engine?

All that extra air getting under our trucks kills us at cruise.

[cougar]

Did some changes to the 91.5 sense my last post as you can see in my signature. My work commute is now up to 25mpg. I GPS'd the speedo to verify accuracy and it is spot on. Checked my 92 as well and found out my speedo is 5% off. So actually I've been getting better fuel mileage than I thought, in the 18-19mpg range.