[THEFERMANATOR]

Originally Posted by ssiredfish

Yea 3mpg difference....doesnt sound like alot but thats a 30% increase for me.

MJ - I was ALWAYS told the same.....thats why I had to ask

I have a 2005 Chevy 2500HD and the boat with my gear comes in right under 4000#(truck excluded)........I also hate that when OD is on with cruise control and I hit an overpass, the SOB acts like it wants to redline to get up it and just guzzles gas.....

I will try w/o the OD on this next trip and see how it goes. At 1200mi roundtrip I need all the help I can get!!! Especially when my normal fuel econ with no load is 11.3mpg!!!! Ol girl is tough but she aint a cheap date by any means......

Put it in tow/haul mode and go with it. No need to shut OD off for that. Heck I've towed ALOT more than that with a 6.0L 3500 SRW, and it towed just fine and stayed in OD. As for revving up, the VORTEC engines do NOT like to be lugged down. They run the best high up in the RPM's, and it is probably helping your mileage in doing so(and also helps your trans).