I tried to search the forum and did not find much information related to my question.
I have a stock (except for the 60 gal fuel tank) 2012 Duramax 3500 HD crew cab, short bed. Previously I had a 2004 2500HD LLY crew cab (also with a Transfer Flow replacement fuel tank) with all the same equipment (tool boxes, etc.) but with 16” tires (the 2012 has 18” tires), i.e. basically nothing has changed weight wise-except for the truck itself. I did a mileage test over several fill ups, driving conditions, weather conditions, etc. and the results are below. One reason for the purchase of the 2012 was for improved mileage.
All Mileages calculated by hand not by DIC
Year Mileage % difference Mileage towing % difference
not towing ( 2012 vs. 2004) (2012 vs. 2004)
2004 17.8 ------ 11.9 ------
2012 15.3 -13 8.2 -31
You can see I am quite disappointed as my 2004 got between 13 and 31 % better fuel mileage. Do these figures surprise anybody and if so any suggestions? The service department at my local dealer says nothing is wrong with the truck.
Thanks
I have a stock (except for the 60 gal fuel tank) 2012 Duramax 3500 HD crew cab, short bed. Previously I had a 2004 2500HD LLY crew cab (also with a Transfer Flow replacement fuel tank) with all the same equipment (tool boxes, etc.) but with 16” tires (the 2012 has 18” tires), i.e. basically nothing has changed weight wise-except for the truck itself. I did a mileage test over several fill ups, driving conditions, weather conditions, etc. and the results are below. One reason for the purchase of the 2012 was for improved mileage.
All Mileages calculated by hand not by DIC
Year Mileage % difference Mileage towing % difference
not towing ( 2012 vs. 2004) (2012 vs. 2004)
2004 17.8 ------ 11.9 ------
2012 15.3 -13 8.2 -31
You can see I am quite disappointed as my 2004 got between 13 and 31 % better fuel mileage. Do these figures surprise anybody and if so any suggestions? The service department at my local dealer says nothing is wrong with the truck.
Thanks
