The RPM to MPH convresion is based upon gear ratios. So if you've got a stock ransmission, and stock sized tires, than the RPM conversion chart will still work. Larger tires will show slower speeds (more surface area), and smaller tires will show faster speeds less surface area). This is also something to remember when buying used cars. Low miles on a car, or truck with large tires are probably not going to be correct. -Robert vin 6585 "X" To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/