Getting Better Mileage From An Older Peterbilt

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.

 

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.

 

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.

 

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.

 

Hi. I own an older Pete and would love to help you out. I average 7.5 mpg pulling a 53 ft flat with an average gross weight of 94 000 lbs. Im not kidding. Took alot of research but not alot of money. Still drive it today. Everyday.

 

How you figure that? I average 7.5!!! 425 3406 b.

 

i have a driver in a t600 425 9 spd 4.11 rear get around 6 mtg ave