SCT received from DC. 91 octane tune successfully uploaded. Big difference! Truck will absolutely roast the rear tires. Long bark when hitting second. Water temps and oil temps operate at the desired 170 degree. Chris needs to fix the 91 octane tune, as the oil pressure guage is not working on current version. After my test ride, i filled up with gas, drove 25 highway miles home, and, averaged 15.5mpg. I normally get 12.0 to 12.2. However, before I was able to actually upload the tune, I did run into some minor problems. I had to update the firm ware on the SCT unit itself. SCT shipped my unit to DC with version 1.16. Guys, this was a very easy fix. I downloaded two things (free) from SCTLFASH.COM, first, the updated firmware (version 1.17) and, second, some software to interface my PC to the SCT. I knew there was a problem with the unit as delivered by SCT, and not anything DC had done. DC does not control the user interface on the SCT, merely the tune file, and, I was getting ECU unock failure message while trying upload the DC provided 91 octane tune. This failure was in the user interface. Any way folks this is one kick ass piece of technology. Chris at DC is doing a great job, and, is working on an updated tune to fix the oil pressure problem. I confirmed that it is isolated to the custom tune itself by loading the stock tune back the ECU, and oil pressure works. I am expecting an email any time with attached files from Chris. I have requested a more aggressive 93 octane tune and 100 octane race tune.