fuel economy

[skipper194242]

when i got my 35 ft. cardinal 5th wheel i got 14.5 mpg on my 2008 chev 3500 dually 4x4. it did not change towing or not towing. now its dropped to 13.2. i changed fuel filter,air filter, no improvement. what can cause a drop in mpg? it is a diesal with allison automatic and 3.73 rear end. thanks.

[h20ski]

Weight, Wind, hills, Sarting and stopping. Have you neen checking it with pen and paper or using the driver information center on the dash? That mpg seems pretty high. The best I get towing with less weight on mostly flat land and 60 mph is about 11.4-12.4.

[skipper194242]

i checked it with paper and pen when i first got truck but going by computer since. will recheck thanks.

[TURBS]

Originally Posted by skipper194242

i checked it with paper and pen when i first got truck but going by computer since. will recheck thanks.

My dic is always spot on with pen and paper.
Bad fuel?
Injector issue?
Injection pump issue?

As stated before wind driving conditions traffic hills

[Great Horned Owl]

With my 2011 Duromax, I notice a difference of up to about 1.5 mpg depending on where I buy my fuel. I'm not certain, but I suspect that it has something to do with the percentage of biodiesel in the blend.

Joel

[great white]

1.3 mpg change is insignificant in troubleshooting whether or not there is a "problem".

It's the difference between idling and not idling for warmup times or how heavy your right foot is or isn't that month....

[skipper194242]

i reset my dic and drove 60 mph for 10 miles had it up to 15.5 good to go. now i have to check with pen and paper. thanks.