`06 LBZ improvement, MPG and power

[Tractorhauler]

Pete,
I do have the LLY with the 6 speed. Just the last 2 days driving my short distance to work, no towing, I am getting right at 16 mpg. I sold my LMM 2007 partially to get better mileage because I became tired the the regen horrible mileage and the fact that I could not do any real substantive aftermarket mods without getting flashes of check engine messages.
Mark

[Kennedy]

Hi Mark, from what I see you have an `06 truck with the LLY motor right?, I, as mentioned got better mileage with my (2) LLY trucks than this LBZ, but can feel the extra power this engine has. I think you have the ability to get even better mileage with yours than I did because my LLY trucks were `05's that had the 5 speed, yours should have the 6 speed which should/could get better mileage due to turning less RPM's, I did notice mine running below 1800 rpm at 69 MPH while towing. I thought with this turning less rpm it would get better highway mileage running empty, but still could not touch either LLY, and the last one was a CC 4X4 dually that weighed a LOT more than my current 2500 HD does. Only thing I have done to my truck is the K&N air filter element, and the Superchips tuner, otherwise its stock.

Wind is more of a factor than RPM in my experience. I'm sure that there are cases where RPM reduction will help, but the Dmax 5 speed is in a pretty good place as far as RPM goes so the extra OD doesn't make a huge difference. The 06-07 LBZ will run pretty darn close to the 05 LLY MPG, but it takes a good tune and restraint on the part of the driver to get it there...

[pete m]

"as far as RPM goes so the extra OD doesn't make a huge difference."


Then why did they add another O/D to the trans?????????????????????? I was under the impression that it was to add fuel economy.

[Kennedy]

My guess would be emissions. Both from the tailpipe and noise.