low fuel mileage
 

After recommendations from members on this site in the Spring, re: srw or drw trucks towing a large trailer and the safety involved, I decided to try a Dually and so far I am very happy.Towing with a 2003 Dodge Ram Dually, 2wd 5.7 Cummings diesel, goose neck trailer, total pkg weighs under 22000 lbs. Don't know gear ratio but 70 mph is 1950 rpm. Only getting 10 to 10.5 mpg. This seems low to me. Any help and where is the first place to look/change ???

Re: low fuel mileage
 

Do you have a tuner or exhaust mods?

I have a 2002 Dodge 3500 dually 2wd 6 speed manual and pull a heavy 48' LQ GN. My truck has an Edge Juice with attitude tuner with 4" exhaust. The truck has 4.11 gears and at 75-78 MPH it's turning 2200. I avg 10-11 MPG and have no problem pulling hills or passing slower traffic.

The tuner makes a huge difference and is like night and day on my truck. The attitude gives you the ability to see boost, EGT IAT, and the ability to switch up to 5 modes. It was well worth the money.

Sean

Re: low fuel mileage
 

I have a Bully Dog. Tried 3 different modes and either one seemed to effect mileage only perf. Recently fried the auto trans and since the rebuild I have not used the tuner. It's got 4" exhaust.

Re: low fuel mileage
 

So is 10 mpg all I should expect? I've heard claims of 15 mpg.

Re: low fuel mileage
 

I thought maybe someone else would chime in?? The best mileage I get with mine not towing is 18-21 MPG, at 75 to 82 MPH, turning 2200 to 2400 RPM. My truck only has 114,000 on it. To be quite honest with an Auto and yours being a 03 that's seems like a reasonable number. If someone is getting 15 MPH there is no way they are pulling a 22,000 lb trailer!

Re: low fuel mileage
 

Repeat

Re: low fuel mileage
 

If you want all the details about the build of your truck, go the the link below and click on "Your Vehicle" and then on "Equipment Listing" and put the VIN of your truck. It will provide a detailed list of the build of your truck in detail, including all options.

It works for any Dodge/Chrysler vehicle built after 1998.

https://www.dodge.com/webselfservice/dodge/index.html

Re: low fuel mileage
 

what do you get when not towing. I have the 99 version and get between 17 and 19mpg

Re: low fuel mileage
 

Sean: The truck and trailer total weight is under 22,000 lbs. Rarely use the truck without the trailer, but if the overhead indicator is at all accurate I'm over 21 mpg.

Re: low fuel mileage
 

Based on my experience with two 5.9 Cummins (both with manuals) 10.5 MPG seems reasonable, particularly towing 70. Have you tried towing at about 1500-1600 RPM? You're likely to get 2-3 MPG improvement and then you can do a cost analysis to see if a gear change is reasonable.

BTW your indicator is probably optimistic by at least a couple of MPG. Also, unless you plan on burning up another stock auto best leave the tuner stuff unhooked.