Question on gas mileage

[Alan Warman]

Out here in Tx I can get 24 empty,and if I am towing the open trailer I get 18-20.Mine gets the best mileage
at 62mph but it takes forever to get any were.Greg how do you like your new Olds,I nearly have mine up and running.

[Myron Piatek]

I have a Dodge 2004.5 Cummins Quad-Cab dually with an auto and 3.73 gears. It has a fiberglass topper that kicks up higher in the back and tows a 26' Pace which brings the total weight to over 19,000lbs. The trailer is still at least 1 1/2 feet taller than the back of the truck. I've gotten almost 13 mpg hand-calculated under ideal conditions, but usually get between 11 & 12. It looses a few more in the hills/mountains on the east coast. It's a time-consuming pain to fill fuel to the very top each time, but it's the most accurate way to check mileage. I usually cruise around 72 mph and, as noted, driving slower picks up mileage a bit. (The overhead computer has never been close, originally and even after a factory computer reflash for mileage, white smoke and computer mileage accuracy, especially after adding the box.)

It's all stock except for a Quadzilla 65hp/125tq tow box and an Amsoil EaA blue air filter. I believe they are more efficient than the oiled K&N and I've heard people debate whether or not the oil from it can actually affect sensors downstream. Drivetrain has all Amsoil: Series 3000 5w-30 diesel oil, Universal trans fluid, Severe Gear 75w-90 in the rear end and truck and trailer tires are kept between 75 & 80 lbs. The box picked up between .5 and 1 mpg. But I've always babied the truck and it has picked up mileage through 35,000 miles. It actually seemed to pick up more after a couple of occasions where I really got into the throttle! I "think" it's finally fully broke-in now after almost 50,000 miles. I also use Amsoil's diesel fuel modifer and cetane boost also.

I thought about a wing/spoiler on the topper, but am concerned about it eventually cracking the fiberglass. Some people have said that a wing at the cab is too far forward to help much. The "bubble" on the trailer front seems like a good idea and I wish I would have ordered it when I speced out the trailer.

I am considering an aftermarket, better flowing muffler and I've read that aftermarket fuel pumps help mileage also. Better flowing air boxes & tubes are suppose to help to. They are expensive and some people have swiss-cheesed their OEM air box instead.

The older trucks should get better mileage because the newer ones like mine have an extra pre-combustion cycle. I forgot exactly what it's called, but it uses a little more fuel. A manual trans should also get a little better mileage over an auto. Then there has been talk of "seasonal" fuel that affects mileage and there is always wind or unnoticable grades in the road.

I did get a 60 gal. auxilary tank and plan my stops in states with cheaper fuel prices. Flying J has good prices, online locations & prices and an RV card that saves 1 cent per gallon.

Amsoil source & info: http://www.thelubepage.com/

[DustyLowell]

We have a 2004 Ram 4 door 2500 4x4 with the Cummins. Average mileage increased drastically when we purchased a 28ft Goldrush. We are seeing around 16-17 mpg towing to MapleGrove from NH.