fuel mleage

What engine? What transmission? What tire size? What tires? What type of trailer? What kind of traffic and terrain? How heavy do you typically run? Do you run local or OTR? How much space between the back of your cab and the front of the trailer?

None of those magic fix-in-a-box type products you mentioned are going to do anything but lighten your wallet.

 

1) Change tires to 11r 22.5 however depending on gear ratios you might use more fuel climbing hills.
2) Progressive shifting, shift low and use rpm's that you only need.
3) Fuel filter makes a big difference, change it every 20,000 miles at least.

 

Yes, I think the flow through muffler is one thing that actually will work to help mpg. I've got a Walker Megaflow, I think it picked up .2 mpg when I replaced the stock muffler with it.

 

5.7 to 6.2 is reasonable mpg for that motor.. I have a ISX Signature 600 and I lost .5 mpg when we switched from LSD to ULSD.. I used to get 5.5 -6.. now all I get is 5-5.5 on average. Less when hauling heavy or wide unusual stuff.. (I pull a RGN).

Those snake oil remedies, turbo 3000 Dvada,dvwhat ever are a waste.
> Save your $$ check your tire pressure regularly
> Run rib tread tires if you can (You don't go into the snowbelt).
> Run slower & like was already said progressive shift.
> "Read the road", stay off the fuel and brakes as much as possible.
> Grease your 5th wheel regularly and check hubs. (A "stickey 5th wheel will cause your trailer to "bind" and not "float" behind you.) If you've ever driven a truck with out power steering you'll know the difference of not greasing your 5th wheel. Hubs run better cool..
> Use good fuel and filters, check all filters often!
Just a few unusual suggestions some that might slip everyones mind but can add some help??

 

I bought the Pittsburgh power muffler and picked up .7mpg on a 05 columbia.

 

What RPM do you turn at 62? I ran a 2007 for 8 months with the same spec's (but will add 10spd with a highish rear ... 1500 rpm at 72 mph) With my foot always to the floor pullin a spread axle flat out west carryin 25k to 48k and idling when needed I consistently averaged 6.6 (without unplugging the EGR). 6.8 or better in cali runnin 60+

This was in a poorly maintained Ryder truck. Came to us with problems, and probably spent a month out of those 8 in the shop. Local shop here used recycled oil on PM's It had over 300k miles on it ... and its last overhead was at 100k

Don't understand your poor milage ... what are you pullin?