I have just recently installed a ScanGaugeII on my car and have been intrigued with the HSD and learning all that I can about this amazing vehicle. I have a 52 mile RT commute each day on a 55 mph speed limit highway and of course run on cruise control at 60 mph. I have noticed that the MG2 RPM = 7000 at 60 mph displayed. So I began to do some research here on PC to determine the gear ratios and the relationship between MG2 rpm and mph. I came across an earlier thread where there were discussion of the improvements of the Gen III over the II. I came across a post by HTMLSpinnr where he gives the gear tooth counts of the complete HSD system. I have taken those gear tooth counts and applied them to the MG2 RPM of 7000 to calculate MPH based on my tire rev/mile. I also found out that the max MG2 rpm = 13500. When using the gear ratios this works out to the Prius max speed of 113 mph. I thought that other newer PC members like me may be interested in these calculations. If anyone sees any errors in my calculations please let me know.