I tried all 3 settings and I was pretty happy with the extreme setting. It is about the same as t. s. t. set on 5/4 (old program) but less egt. Boost is also funny it sits around 25-30 untill I hit O. D. then it is around 40-45. I am going to do a bunch more testing today. Could not find the speed limiter removal part of it. I did a few runs with tst on different levels but I think I am walking through my converter. D. T. T. stuff is leaving wednesday, should have it in next week some time. B. T. W. My throttle stuck wide open tonight for about 15 seconds and my park brake light is on . But it is -40 Not fun when that happens.