I have a question. I got my SCT SF3 today, and loaded the performance tune. At first I told it to lock convertor in 1-2-3, firmer shifts, turn off EGR, etc... Well, the locked convertor I assume is for WOT, balls to the wall throttling, because on the street, under lighter to moderate throttle, it would shift and just drop out to nothing for a second, enough to make my turbo "huff" and make it sound like someone had put a straight shift into too high of a gear, and was lugging it. I went back in, set convertor lock to normal, left the shifts firm, made sure I had the correct axle ratio, and it shifts MUCH nicer now. OK, to my question: what does convertor lock @ CT mean, and on the speedo calibrate/tire size, how do you determine how many revolutions per mile a 305 70R/16 makes? It would be easier to list sizes, but they don't, it asks tire revs per mile. Maybe there's a chart? A calculation? And lastly, does anyone have any suggestions on the trans pressure settings from one gear to another, or should i leave that alone? I just want to get it as good as possible, have good solid shifts, but not make it shift TOO harshly for a DD until I get custom tunes on payday.