All you 20 MPG guys...

[btoscano]

Are you getting that at 55-60 MPH? Do you live in Iowa or Florida where its essentially "flat" ?



What MPG do you get driving 72-77 MPH actual (on my truck that's 78-82 indicated)? I'm getting 16. 6-17. 1 and really would like 19-20+. I want to know if I would need to drive slower or advance the pump because I can't flatten Tennesse!



Thanks,

Brian

 

[BJMarshall]

This is probably not an option, but the only suggestion I have is to slow down. It makes a tremendous difference on my truck from running 60-65 and then going 70-75. Even with the mods I still get 20-21 if I keep it around 60-65.

The difference between 60 and 70 on a 100 mile trip is only about 15 minutes.

 

[csnider]

Hmm,

I would think if your speedo is 5mph off, that your odometer may be giving you false info as well... .

I think letting the engine breath better would be your first improvement. BHAF-AFE-K&N air filter. . with 212K it might be a good idea to have your injectors cleaned and recalibrated. The timing advance would help aswell. . I think with a 5 speed stick your mileage could be better than 17mpg. A lot just depends on how you drive...

I average 17-18mpg pulling a 10ft enclosed wells cargo trailer @55-60 mph but I step lightly on the throttle which is no fun for most people. . I can do a little better without the trailer @ 70+mph . sometimes I just get a tank of fuel that isn't as good and my mileage drops... ... the 4WD tranfer case cuts into you mileage a bit I would think... .

 

[WJune]

Honest 24 mpg ! My 83 yr old mother has a mint Az 95 D 250 with streamlined topper. It looks like a suburban. Two yrs ago she got ticketed in Kansas doing her age 80 mph. Trips from Az to Wis. she gets 24 in the summer. She always doe's speed limit, or more. She is finaly down sizing to a mini van, and the Dodge is 4 sale. The only reason I don't grab this fuel pincher is that it's too nice for me. I need a 4x4 I can take into the woods.

 

[Grizzly]

Are you getting that at 55-60 MPH? Do you live in Iowa or Florida where its essentially "flat" ?

What MPG do you get driving 72-77 MPH actual (on my truck that's 78-82 indicated)? I'm getting 16. 6-17. 1 and really would like 19-20+. I want to know if I would need to drive slower or advance the pump because I can't flatten Tennesse Brian

Not even close!

 

[MMiller]

Are you getting that at 55-60 MPH? Do you live in Iowa or Florida where its essentially "flat" ?



What MPG do you get driving 72-77 MPH actual (on my truck that's 78-82 indicated)? I'm getting 16. 6-17. 1 and really would like 19-20+. I want to know if I would need to drive slower or advance the pump because I can't flatten Tennesse!



Thanks,

Brian

Well, I live in Iowa and it ain't flat! I find it hard to believe that were I live is why I can GET good economy. Notice I say can GET, the way I drive directly effects fuel economy. When just running around to town and 2 lanes, my mileage suffers. When I get out and run it down the interstate without stopping is when I get good economy. When I took my truck to AZ one weekend, we traveled between 70-75 all the way down and for the trip averaged 24 mpg. I think it has more to do with how you drive, and overall speed. If I hang right around 70 mph, that is about the best economy. If you drive with no smoke from the tailpipes, low boost and pyro, that is going to give you best economy.



Now Kansas is flat, Illinois is flat, Iowa is not. I suppose compared to TN, IA is pretty flat, but the hardest towing I know is driving from Davenport Ia to Council Bluffs on interstate 80, seems like your going up hill most of the way.



Michael

 

[btoscano]

This truck has a Cummins reman pump and injectors that are a few weeks old so they shouldn't be worn. (The pump AFC fuel pin was sticking and making metal and the injectors were 900 down. ) There is no noticable smoke out the exhaust but the side of the rear bumper is sooted up.



The new injectors pop at 3800-4000 and the pump is currently set 3/16" above the timing cover index mark. (I bumped it 1/16" last week and saw a 0. 4-0. 7 MPG improvement). I am considering upping the timing a bit more.



Brian

 

[btoscano]

I am really thinking of getting permanent gauges for this truck. But I've been holding off... once I get 'em I *know* I will want more power and right now want to spend the money on land & farm equipment.



Brian

 

[jbolt]

When I drove my 93 off the dealers lot in 93 it averaged 17-18mpg. A few times I got close to 20 on long highway trips. When I put the larger tires on it dropped to 15. 5 to 16. 5mpg. 95% of my driving is around town, in the hills and short hops on the freeway. I haven't heard of many 4x4s getting much over 18 at best but its a heck of alot better than my old 87 gasser w/440 that got 8mpg on a good day.

 

[Chris and Sam]

fuel mileage

well, out in California my 93 in my sig gets 21-23 at 65-70mph, and gets 16 pulling 10k of weight. My crew gets about 20-22 at 65-70, with a best of 25mpg! both trucks have 3. 54 gears. Oo. Oo.

 

[DieselTweaker]

when my truck is on the road, and nothing but highway miles i can turn 16-17mpg at 70mph, but if i do some intown driving or strech her leg's a little more than normall it drops to 12-13.

 

[JLEONARD]

I can get 24 if I take it easy and stay at 60 on the highway.

But normally I get about 21/22 doing 80% expressway driving at 70/75

 

[TKingsbury]

I get 18 regularly with mine during mixed driving. Here in Cali, I got 21 on a trip that was mostly steady driving in the 65 mph range. In Idaho, I got my best tank ever, 23 mpg. I don't know if I got an exceptional batch of fuel or what, but I didn't argue.

Travis. .

 

[Joseph Donnelly]

I know a 2004 isn't first gen, but it got 22. 5 mpg on its last trip across mountainous northern AZ going from Albuquerque to Las Vegas at 72 mph.

 

[MMeier]

My old '93 W250 CC would get around 21-22 MPG on a highway trip maintaining 70-75 MPH the whole way. Would drop to 13-14 towing 6500# enclosed trailer at those speeds. Truck had the 5 speed and 3. 54's

 

[CGauthier]

I just changed my tires from 255 85R's down to 235 85R's and I'm anxious to see if that makes any kind of difference on my mileage. With the 255's around the city mainly mixed in with a bit of hwy driving the absolute best mileage i could get was 16 mpg, and driving like that in the city is so slow it's unrealistic lol. I still have the original stock injectors and a reman pump to replace the defective original. I'm a little surprised how many posts we're seeing on this topic these days... .





Carl G

 

[Niki]

I had a stock 91. 5 D250 5 sp 3. 54 that never got below 18 no matter how you drove it, got 20 going 75-80 on the highway w/ a 20' boat in tow and a little over that empty. Had a 91 W350 SRW 3. 07 727 truck that got about 18-20 combined driving, probably my favorite Cummins to drive- tons of stock power and a nice shifting auto. Also had a 95 CC 4x4 5 sp 4. 10 that got terrible mileage when it had the stock donuts(245/75-16) on it, like 16 driving around and 13 going 73, lifted it and put 315/75-16s on it to cut the 4. 10s down a little and got about 15 highway@75 and 18 around town, one time got caught in a terrible snowstorm on a 350 mile trip to Wisconsin and got something like 22 or 23 because I only drove 40-45 all the way, very low RPM, in 4high too. It seemed to me in my experience that that 95 motor just got so inefficient after 1700 RPM(totally stock except for modified airbox and no cat) whereas all my VE pump motors especially the 91. 5 were revved much higher and got great mileage. I'd love to find 4 people w/ standard cab 4x4 5 sp 3. 54 stock trucks say a 90, 93, 96, and a 99 and drive 200 miles steady highway 75 MPH and see how they do w/ mileage. That's a pretty realistic representation of how fast most of us drive on the highway I think.

 

[btoscano]

Seems that fuel economy is all over the place - Some get high, some get low.



For the record, in the Southwest I typically get higher MPG in every vehicle I drive. I am not sure why but I suspect the higher altitude, drier air, and flatter roads contribute enough to offset the higher speeds.



I will put some more effort into getting the optimal timing.



Does anyone know what the Cummins dealer would do if I took it to them and asked them to set timing on the pump?



Thanks,

Brian

 

[btoscano]

One other fuel economy question - would BFG A/T KO 235/85 R16 tires hurt fuel economy over a more street tire?



Thanks,

Brian

 

[DSteimle]

my 93 d350 gets 21-22 at 60 and 19-20 at 75. wifes 93 d250 gets 17. 5 no mattter what i think the torque convertor may be too loose on hers(searching for a 47rh to put in now). my torque convertor is my left foot