I talked to a friend of mine at the dealership. He is a mechanic. I have been a little unsure if I wanted to have the reflash done until he told me that it bumps your horsepower up to 390 and is supposed to help mileage a little bit. He said GM isn't advertising this. I'm assuming this is so they can anounce it for the upcoming trucks. He just bought an 08 LMM and he made sure it had the reflash done before he drove it home. I was just wondering what peoples thoughts were and if they have noticed horsepower increase. I'm not sure if you would even notice it unless you were pulling a trailer up a hill you commonly pull up.

cannot feel a bit of difference.

It's always funny with the "secret" GM stories, they never advertise the increases in mpg's or power. Your friend is jerking you around. Why on earth would a manufacturer create an update that gets 25 more hp, and better mpg's (in the current state of cost of diesel) and not advertise this everywhere? GM techs that are on here would be the first to tell if this was reality, but I think the friend is just making something up here. Chris

I "thought" I detected a couple more HP gain myself after my reflash:rolleyes:, but...nope, guess not...sounds like a really great rumor to spread though.
Since the reflash, everything still seems the same as before the reflash, hey...that COULD be a GOOD thing:D

The main reason for the reflash is to keep your truck from not starting intermittently. Dunno why you'd be afraid of that. And the hp gain is bull. Could it? Possibly. But thats not its goal.

Spoke to my buddy who is the head of service for a dealership here locally that sells/services alot of diesels and when I mentioned the extra 25hp gain with the flash, he busted out laughing and then choked on his food.

i don't believe it either.