I'm not going to go into brand - I'm not here to advertise for anybody. But I just put a performance module in the OBDII port of my 2010 SSV 5.3 and am experiencing a significant immediate improvement in engine performance. There was always about a 1/2 second stumble when I accelerated from a stop - I figured it was the active fuel management system. It wasn't terrible, but you noticed. After I put this chip in, throttle response is much better, with no hesitation, and freer revs through every shift point. The truck is actually pretty quick now, and it pulls all the way to 99, where it is apparently governed. Passing on the freeway - throttle response and revs are immediate, smooth and seemingly effortless. The literature that came with the module says it should take 150 miles of driving to fully integrate, and that there are fuel mileage results as well. At this point though, you can still see the gas needle move. My test circuit was 26 miles and it appears I used an 1/8 of a tank at 8.3 mpg - this was a first test so I had my foot in it a lot. If you want the manufacturer, IM me, although I'm pretty sure the different brands are basically alike. Before the chip the Tahoe wasn't exactly fun to drive - or easy - it's a truck. My P-71 was quite a bit quicker - especially to 50. Now I think this one might have an edge.