I am a newbie here but I have been reading for several days and most everyone can only get maybe 18-20 mpg out of a 24v. Trying to figure out how my truck gets such good mileage. Can get 24+ with a steel Knaphiede bedcover that wieghs 1200#. I AM NOT COMPLAINING!!!!!! Just trying to figure this out... No electronics on truck. tires 245/75-16LT 3.55 auto

Driving habit? Are those tires oversize?throwing off odometer/overhead mileage calculator:shrug:.

Tires are stock size, Drive very conservative..No Lie-O-Meter all hand calculated full to the neck everytime.

Good tune is all I can say leave well enough alone... Now as for myself and ISX we've been studying this and not found a exact answer to why some people get super good number for MPG's and others are in the dump. But driving habits, speed, weather, tires, gearing, etc all play a role in the MPG game...

I got a few questions that might help in this endless quest. List the speeds and MPG for them if you know them. As in, mine would be 21mpg@70mph, and it gains 2mpg for every 5mph decrease. Does your mileage change in the winter? Do you run a chip of any kind or is it stock?Are you hand calculating mileage or going by the overhead?I am almost beginning to think there are different "tunes" on the programming of the trucks. Most of this is not apple to apple conditions though. You are in, well close enough to little rock which isn't very much elevation, same as here, but then other people are running higher elevation. I don't know how much this effects things, but I got the same 21mpg going to denver at 70mph as I got going to detroit. So it seems I get a universal 21 at 70 so it seems like conditions don't matter that much. If the VP44 wasn't such a mystery as to how it worked (timing) then I think it would be easier to figure out all these mpg issues.

Yeah, I am not complaining but really I am scared to do anything to cuz it might screw it up...LOL55=24+ Dont really see a drop in the winter. No chip or injectors. Stock. No overhead.

My old beater..Love that truck...LOL

Yeah, I am not complaining but really I am scared to do anything to cuz it might screw it up...LOL 55=24+ Dont really see a drop in the winter. No chip or injectors. Stock. No overhead.

See Mike told me the stock truck won't get anything for mileage. Making me think even more that these things are programmed differently or something. Weird thing is, the other guy I know getting 25mpg has a nv4500, edge juice, 100hp injectors.. In other words, nothing is as expected with these things. Maybe they are all programmed the same, I don't know. Guesswho512's truck is identical to mine even down to the paint color, and he doesn't get anything for mileage, yet I get 27 at 55. So it would be really neat to trade him trucks and mess with his til his gets 27 as well. If they are the same trucks, it will take the same fuel to get it down the road (and I really don't see a difference in mileage even with 2 engine blocks in the back, so that "24V get less because they weigh more" is BS). The other thing is that I got the same mileage completely stock (muffler and all) as I do now. Now there are compression ratio differences between the 12V and SO 24V, but you and THracing and the other guy who all get exceptional mileage all have SO 24V's, with and without mods. That brings the factory programming back into the picture. There just has to be something different in that aspect.

Probly should contact your states AG dept Division of weights and measures, the pump is probly off in your favor and the station in losing revenue.

I will admit that I drive trying to get the best mileage. But as you can see the bed cover is higher than the cab and bang heavy. Truck rides better but it has to use more fuel with it. I would love to see what THIS truck could get with tuner, injectors, etc. I had an 06 dually that would not get better than 17 ever..go figure..

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I wish.........

I will admit that I drive trying to get the best mileage. But as you can see the bed cover is higher than the cab and bang heavy. Truck rides better but it has to use more fuel with it. I would love to see what THIS truck could get with tuner, injectors, etc. I had an 06 dually that would not get better than 17 ever..go figure..

See thats another thing. Dorkweed has no problem getting into the 20's with his CR.

I think there are 25 or something ECM's out there for the 24V VP44, so I wonder if finding one the same model # as yours would get the mpg gain. Not sure if you can just plug and play like that though.

I have had several cummins and one duramax but this truck is the best for mileage.. Not the strongest but good enough..Worst was one of the first 6.7...Dodge bought it back....Hated that truck..LOL

Gentlemen, What if, we did a data base build, cruse control ON MPG @ 55@ 65@ 70 Outside templevel highway or average coming and going at speed. altitude+ any other pertinant data? Then look at the performance and see what possibly makes them best, or worst.Might be a little much, I don't know, I'm new to a couple things here. Comments? Gary

That would definitely require much data with way too many variables...LOL Boils down to I got a good one:hyper::hyper::hyper::hyper:

yes you did!

Lets see if I can get some more thoughts... I hardly ever pull a trailer with this truck any more. Been reading up on water/meth inj.. What if I ran the turbo over the top straight in with a 50/50 meth...Quicker spooling? Better mpg? Any thoughts?

Lets see if I can get some more thoughts... I hardly ever pull a trailer with this truck any more. Been reading up on water/meth inj.. What if I ran the turbo over the top straight in with a 50/50 meth...Quicker spooling? Better mpg? Any thoughts?

Keep something in mind... More boost pressure = More fuel used = lower MPG's High pyrometer temps = More fuel used = lower MPG's Keep these two gauges low and high MPG's will happen...

My average is 16 if I drive it easy or hard.

Lets see if I can get some more thoughts... I hardly ever pull a trailer with this truck any more. Been reading up on water/meth inj.. What if I ran the turbo over the top straight in with a 50/50 meth...Quicker spooling? Better mpg? Any thoughts?

No - leave it alone. Serious.

Lots of reasons.

I have one.

I see only two reasons

1) Heavy towing on non stock truck

2) High Performance (Dyno, High HP etc)

--- Update to the previous post...

Probly should contact your states AG dept Division of weights and measures, the pump is probly off in your favor and the station in losing revenue.

No kidding - this make the most sense.

The problem is its hard to compare. Mikes truck is different to mine is different to ISX. Mikes driving (hills) is different to mine (hills/city) is different to ISX (flat).

So unless we swap trucks ....... then ??

But with regards to your truck - if its truly 25 ..... then - don't touch it with a thing Thats what we all "aspire" to

sounds good to me I was just throwing that out as a thought in my warped little mind!!!!

MPG is a reflection of equipment and driving style.I previously had a 88 F250 460 gasser, got between 7 and 9 Mpg, so to say the least I have that beat all to He__. :cry:Currently my hand calculated mileage by the fill up is;Highway @ 65-70 = 19 to 20 mpg.City = 14 to 15 mpgTowing = about 13-14 mpg (7,000# 5th wheel 12' tall).Did I mention I love this truck!:hyper:F250 ate a qt of oil about every 1,000 miles.Cummins with 239,000 still full at 1st oil change @ 4,000 miles.