before I talk to the service manager I want your input .I have a 2004.5 D/A LLY CC 4X4 with 3300 miles and I'm getting 19mpg with the A/C off running 68mph. Same speed with A/C on and I get 17mpg. Pulling my 4500# boat on a tandem trailer with A/C off I get 12-13 mpg. Pulling boat with A/C on I'm only getting 10 MPG. With a head wind figure 1mpg less. My 2001 6.0 gasser got 10 mpg pulling the same boat and it had 230 ft.lb. less torque. Why would the mpg drop so drastic pulling the boat. no smoke from exhaust, could it be bad injector? lack of turbo? need to be reflashed? HELP


THANKS IN ADVANCED

how fast were you driving with your 6.0 gasser? Same speed. Were you able to maintain the same speed going up hills with it? I'm not sure what would be the problem. Maybe you just had a really good 6.0 motor. Some are really good and some do really bad.

talked to the service mgr. and he agreed that 9 mpg difference from unloaded to pulling 4500# boat is to much. I mentioned that I would here a clatter\ pinging sound under a load going up a hill or overpass. The man said it sounds like it could be the injectors, this may be why I'm getting bad mileage under a load. Taking it in tomorrow morning, will get back afterwards.

Makes sense if it's clattering. I would also agree that the 9 mpg difference is way too much.