I also run a bellydump in Oregon, just a couple hundred miles south of you. I have never checked what the MPG is, I just watch how many gallons per hour I use. I ran 1000 billed hours and only put a little over 25,000 miles on it. I have an 86 Freightliner with a B model Cat, 13 spd, and 3.73 gears and I averaged the exact same hourly fuel use as a neighbor did with a new KW dump truck. He runs 54,000 lbs and I run 80,000. I was really pleased with that. I would have averaged 4.5 mpg.

I'm not sure what kind of work your doing with the bellydump, but mine was a mix of paving, building roads in subdivisions, and transfering rock from one pit to another. The paving jobs would get down to 4 - 4.5 gallons per hour while the jobs running between pits would get up to 7 gallons per hour. If your running hourly then you might start watching this so you can see which jobs are the prefered ones. And if your sitting and waiting for something more than a few minutes, shut the truck off. Some paving jobs I have had to sit so long waiting on a breakdown or something that I have had to start the truck to rebuild my air pressure. Those are my favorites.

Stretch it out and double frame it. You can always put a bottle of propane to it. That will do a lot.

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Pain is weakness leaving the body.

As I write this I'm having a 10-12 yard dump box put on my truck. Think the mileage may improve considering the weight I'll pull will be substantially less. Have been told dumps are always needed even in a bad economic year. Having the frame doubled and found a used box just a few years old for $6750.00, not a dent in it, complete with all components (same box new is $12,000+ out of Bend, OR.). I may make less per hour but the chances for work are greater than with a bottom dump. Bottoms are too specialized and seasonal for me trying to pull one with the mileage I get.

You're right, rjmcgee, on looking at the hourly aspect of operating, particulary running just local. Running my truck as a bottom dump I rarely had a lot of sitting time and was on the go from the time I signed in until I signed out. My jobs were almost 100% paving. It wasn't uncommon in a 12-hour day to run 350-400 miles so I looked at mileage more than an hourly rate.

I realize I'll never see the mileage the newer trucks get but even a .5 MPG improvement would help, especially when fuel prices are what they are ($4.15/gallon at last check in my area).

An interesting note: I did some calcs and if I'm running a bottom dump with someone else who gets 6.5 MPG and we both run 400 miles in a day I'm burning 27+ gallons MORE a day than he is. That's not what I burn totally but MORE than what he burns. That's a lot of extra bucks I spend in a day on fuel compared to someone else who gets better mileage that cuts into my profits. I have a real incentive to try and improve the mileage, even as a dump.

At this point as a dump it wouldn't hurt to change the gearing from 4:11 to 3:73 +/- plus add a clutch or air fan. That would help a lot.

Thanks for all the replies!

Rod

Thing is your running a SC 350 cummins, them suckers need to be wound up to move, you wont see any better than 5mpg if lucky running around empty. I had a buddy with a 87 FLD he put a 350SC in it, running for landstar with hardly any weight half the time doing 55mph and his average was 4.9mph. Most mechanical engines are stuck in that 4-5mpg realm, its hard to get any better milage out of them unless you are making 600+hp.

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LOAD EM LIKE RAIL CARS, DRIVE EM LIKE RACE CARS!!!!

To put it bluntly...The truck is under azzed....It should do better with the dump bed on her but chance are she won't.

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NO HABLA JIBBER JABBER

"Haven't I told you a million times not to exaggerate"

Every so often, I like to stick my head out the window, look up, and smile for a satellite picture

CBA # 454

I owned an 85 Brigadere dump with a fairly hot BC 300, 9 speed, 3.90 rears on 11R 22.5 The bed was 16 ft, and I grossed 54-56k every trip. If I didn't have to hit the interstate at full speed, and just stay on secondary roads, I always managed 7-8 MPG.

Gearing, and most importantly rpms, will make a big difference. A small cam will not do what a big cam will, but you should see a pretty good increase. It will help having the load all on the tractor drives instead of dragging it behind you, plus you have 8 less tires to move.

That is a real good price on that dump unit. Be sure and don't leave too much overhang behing the rear tires, or the bed will botton out in the asphalt spreader. My axle was at the extreme rear, really a little too far back, but it was enough to just get me up one step in the bridge law formula so I could gross a little more, which with gravel I was paid by the ton to haul.