What's your 1st gen fuel economy?

[AlK]

I have kept track of all my fuel slips for over 90,000 km and the average mileage is 18. 25 mpg. Over 90% of my driving is in town. On the highway the average mpg is between 20-23, depends on how much of a hurry that I am in when I am going up some of those small hills that we have in B. C.

---

Al

 

[JIM S.]

my dads truck, a 90 5 speed,2wd, gets 25 on the hiway. two years ago him and I went to california by way of hwy. 50 and when we fueled up in at our destination we did the old miles traveled times the fuel put in and the numbers said right at 25 MPG. when I drove I kept it right at about 73 MPH and when dad drove he was around 65-70.

 

[JLEONARD]

I get 24 mpg consistantly. I drive in Ct (many hills) and 75% of my driving is at 65-70 mph, the rest in town, mostly with no payload. I have a recently (6 months ago) aquired 91 D 250 2 wd 5 spd. Don't recall the gear ratio, but I have 85 series tires all around. Truck is 100% stock.

 

[Mgrant]

Lets see, here in North Idaho, average highway mileage is about 19-20 empty. Which is good considering that many of the highways around here go up mountains, not hills. Around town and some towing, 15-16 is the norm. The absolute best, 23mpg on ideal highway conditions. The absolute worst, 11. 5mpg pulling a 12,000 gooseneck up a 16% windy mountain road in the Gospel-Hump wilderness, in 2nd gear 4WDLo.



92. 5 W250, 4X4, 3. 54 with 5 speed. 16cm housing with mild pump adjustment, Isspro guages, BD engine Brake with heavy valve springs, Borgeson stearing shaft.

 

[CrewCabDiesel]

Highway only at 70mph, 23mpg.

highway only at 80mph, 20. 5 mpg

city/ highway average 18. 5 mph

worst milage ever 15mph,

loaded to the gills with equipment and 5 adults & 32 goose neck and one very large CAT back hoe.

 

[NOMOFO]

13 to 15 around town depending on foot. Best ever 17. 5.

Maybe indication of timing out and/or impending fuel pump demise. There is an obvious waste of power in this frickin' auto trans too. Savin' up for DTT or maybe NV4500 conversion.

 

[DJP]

With the Lucas injectors, and Banks intercooler I average somewhere between 20-22mpg, depending on how much city traffic I hit, and how many tailgaters I diesel fart .

 

[scott4glamis]

hey NOMOFO try adjusting that trans, you can adjust the bands, one band adjusts from the outside of the trans the other from the inside. get a service manual, an inch pound torque wrench, a filter kit and some transmission fluid( use only chrysler 7176 spec fluid!!)

it is very easy, just follow the manual. it makes a big differance if it has been many miles since the last adjustment, then all you have to do is make sure the kick down is working properly and adjusted according to the manual. also some 235 85 16's will help.

 

[F Simkowski (In Memory)]

A properly set up 1st Gen will get 20-22 mpg.

This will include the proper injectors,exhaust, and turbo 16cm2 hot end.

If you want to fool around... . go ahead and spend your money and time...

Frank S.

 

[NOMOFO]

Frank, would this also include a 1 ton 4x4 automatic that routinely carries around 1,000 to 1,500 lbs? If so I would sure like your recommendations on the proper setup. I have a 16 cm hotend on a second turbo. Am running a 12cm currently. Have not noticed any fuel economy changes with 12, 16, or the 18. 5. Still have stock injectors but have Lucas' on shelf. Have p&m to build 4" exhaust ( all mandrel bent parts ). I suspect pump, lift pump, timing, and transmission adjustments are all possibilities. Comments please? TIA and Happy New Year to all! Cheers, Bob

 

[AMatsonIII]

I am getting around 25-27 over the highway empty.

89 Dodge d250 727 3spd w/ gearvendors under overdrive

Pump tweaked, 3in straight back

 

[JFitzgerald]

Problem?

Seeing all the figures reported for intercooled W250's (ranging from 18 to 22 mpg) makes me wonder if mine is extra thirsty for some reason, or maybe it's driving styles.



When I first bought mine this past summer, it would get 17-18 on 285R-75/16 all terrain type tires.



Just to experiment, I ran a tank on the stock-size (235R85/16) set of tires I got with the truck, and got just a hair under 19.



Later, I turned up fuel, then replaced tires and wheels with 33x12. 5x16. 5 BFG mud terrains on aluminum wheels. It has been getting 16-17 since then. When I tow heavy, I get about 12. When I run mostly highway (empty), it gets about 17.



I suspected dirty injectors, so I started using Power Service diesel fuel supplement + cetane. It does make the engine run noticeably better, but didn't effect mpg as far as I can tell. After a couple tanks of the supplement, the engine runs much smoother at low RPM which tells me it has cleaned the injectors.



I don't hot rod very often, but I do like to feel the power now and then, or fog a tailgater. I normally run 60-65 mph. I like the low end of the Cummins and use it by shifting at fairly low R's. Soon I hope to have a 12 cm housing which should help me there.



Anyone have any ideas where my fuel might be going? I have a feeling it has to do with my new tires.

 

[Harlan]

Fuil Milege

I have run 33-12. 50-16. 5 and 305-75-16 for tires since my truck was new. The other day I put Michlins 235-85-16,10 ply steel side wall M&S on and my miles came up 3 miles to the gal. I could not beleave the fifference. Runing 60Lb pressure. Will never run wide tires agen unless I need the flotation. Have my old set of 16. 5 still mounted. Do not go in sand with the Michlins though for you will be calling a tow truck, if it can get to you. Now I am up to 22mpg.

Harlan

 

[JTMcCracken]

Sorry but my truck has never been driven empty, what kind of wierdo would buy a 4 wheel drive 1 ton with 4:10 gears and drive it empty?

 

[Matt S]

JFitzgerald,

Did you correct the odometer with the tire changes?

 

[JFitzgerald]

Originally posted by Matt S

JFitzgerald,

Did you correct the odometer with the tire changes?

Yes Matt, I used the tire size calculator at 4lo.com and came up with a multiplier that I use to figure the mpg.



It shows a (stock size, I believe) LT235/R85-16 having a 31. 7" diameter, and the BFG site shows a 32. 8" actual diameter for my new tires.



32. 8/31. 7 = 1. 035 rounded off



So I multiply my trip odometer reading by 1. 035 to get my actual miles. Or, is this incorrect?



I like the ride, traction and looks of these BFG's, but if they're costing me a few mpg, as Harlan seems to confirm (thank you Harlan), I may switch to a tall, skinny tire closer to stock size. Anyone interested in a set of BFG KM muds w/ under 5K miles? Problem is, they don't make a tall skinny for my nice 16. 5" wheels. Might have to go back to a 16.

 

[CToney]

The milage in my brother's truck seems to be better than my extended cab. They are identical for mods. They both have the 16 housing but his is a holset and I'm not sure what mine is. And for some reason his sounds louder than mine. They both seem to have the same amount of power. The only real differences are that I have knobbier tires and a different visor. He has a lund where I have a cheaper Canada west visor. The diffence is abouot 2mpg towing and 4mpg or better empty. Would the visor and tires make that much difference. How much does timing affect milage?



CR Toney

 

[TSkibyak]

I average about 22 to 24 on the hwy unloaded

91 reg cab 4x4 727 with 4. 10

 

[Moab4x4]

When the truck had a worn out motor (it had been toasted and 4 scuffed cylinders, smoked and with blowby) and the stock automatic I got 14 high and 9 loaded.

New motor with 5sp. I just got 19. 5 unloaded although I did encounter a mountain snowstorm that slowed me to 25-30 for an hour or so of the 400 miles.

93 W350

 

[Featherman]

I'm losing

I have not driven the truck much empty and use it to pull a car single car trailer, plus I have probabaly the worst combination, 4x4 dually, but my mileage is also sucks.



I've got the new turbo, new PODS, 3200 spring and have not installed yet (haven't gotten the courage to dive in). The motor runs sweet and didn't want to mess with a good thing, but the mileage may force me to dive in.



I average anywhere from 10-14... ... ... ... ... ... ... ... which is not that great.