Jared Peterson

Im sure this is pretty much a dead thread now, but anyway, I’ve always wondered about this feature but just finally got around to doing some searching on what others know about it.

So 1st let me say that I used to have an 08 Duramax & I had a tunes built for it that I could switch on the fly. One of the tunes was a “tow” tune. Now, I’m not sure about the other engine gens but the LMM engine variant of the Duramax had variable turbo geometry (turbo veins). When I used the tow tune & took my foot off the throttle the CPU would close the veins & build a couple lbs of boost @ 0% throttle and slow the truck down. It was more noticeable when going down hills & more so when pulling some weight.

I was actually wondering if that was something that was programmed into the 2.0T from the factory or something. I don’t even know if the turbo is variable or what but I guess I always thought that might be possibly what it was doing. I use the feature all the time going down the mountain grade from work. Yes, there are always cops waiting to bust ppl not paying attention. Speed limit is 55, I’ll set cruise at about 45-50 and then just barely put the slightest bit of foot on the accelerator to keep it from engaging. Once I hit about 65-69 I let out and it brings me right back down. Rinse & repeat. I was hoping that it maybe would save on brakes a little while also being able to leave it in 6th gear & save some fuel.

Anyway y’all, it’s been fun. This is actually my 1st posting here. I’ve had the car for almost 4 years now & I like some things & some things that I don’t get why, & things that I just hate about it but it has always gotten me to where I needed.