Well i guess after bashing superchips last night on the web site mabye they got the hint. They notified me today that they found the problem with the tune and it is not just my tuner it is the whole tune file. All 4.8 08 silvarados tuning file are wrong and superchips say they are dillegently working to fix the problem. They are saying that the 08 4.8 is more like the 09 4.8 than the 07 4.8 and they are needing to have the fuel and spark delivery and timing set a diffrent way. They said that the guy that wrote the tunes is no longer there and they have a new gm engineer fixing the problem. They said that the old tune was set by the Inlet air temp and something else it got a little confusing. Pretty much they are saying that the new file will allow you to tweek the fuel curvs and spark unlike the old files. They also said that the 4.8 is a little more finike to tune than the 5.3 and 6.0. Pretty much they admitted that they messed up and that i wasnt getting the power that they promissed. They also said i would not only get the power promissed but i would get probally 10 more than advertised. WE will see. Just in case they extended my satisfaction guarentee till the software was complete and are going to give me ample time to try the product out after it is fixed. They are saying it should be completed in a month or less. Well i have a paperweight right now and if it dont work better when the issue is totally resolved I am gonna get my money back and get a Diablo preditor hopefully the trinity will be out by then also.