[PeteDrez]

I read about the BD Power Pup and its ability to improve fuel mileage 2 to 5 miles per gallon in tow/haul mode and wonder why Duramax engineers are missing this opportunity to improve their product. This situation does not compute in my brain. I am confident that Duramax does not have all the dumb engineers and all the smart ones are at BD. There has to be more to this situation than what I am reading. Is BD "leaning out" the fuel mixture ratio to burn hotter? That would be great for power and mileage for a while until you burn the innards of the engine. Please help me understand the facts here. I do not add/modify things until I am confident I understand what I am doing, and I do not understand this. Thanks

 

[Slick]

A lot of it has to do with emmissions I think. The tuning companies can take advantage of more efficient tuning, because they don't have to worry about meeting any emmissions regs.

On edit: I think 5 mpg is very generous. If you can keep your foot out of it, I would think 1-2 mpg will be about all the gain that you will see.

Some people even see a drop in mileage. With the new found power, some just can't keep their foot out of it, and end up gettin worse mileage. They do have more fun though.

 

[Beauford T]

not sure about the lbz but on my lly 5mpg is not at all generous!!
running the 90hp setting power pup!!

 

[Max Power]

Basically to increase fuel mileage you need to do the same amount of work more efficiently. Generally speaking the reason tuners such as bully dog get better fuel mileage then stock is that they increase timing and various other factors that can cause a more efficient burn and in return you get better mileage. I would guess that part of the reason gm wouldn't increase timing for the same results is because they don't want the additional timing rattle that advancing the timing can cause.