Armand (0.00595) * (RPM * r) / (R1 * R2) = vehicle speed in miles/hour where: RPM = engine speed, in revolutions/minute r = loaded tire radius (wheel center to pavement), in inches R1 = transmission gear ratio R2 = rear axle ratio You can also google speed vs rpm calculator I have a 2.73 ratio in the rear axle, the rear tires are 245/45R-16. The tire is 24.7 inches in diameter The T5 has a 3.35 first gear. Fifth overdrive is .63 Can anyone expand on this? What speed will the car be going in first gear at 2000 rpm. What speed will the car be going in fifth gear at 2000 rpm. I know there's a formula for this bt of course my used up brain cells cannot figure it out. thanks, Armand ------------------------------ _______________________________________________ -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://list.amc-list.com/pipermail/amc-list-amc-list.com/attachments/20120626/e093f8db/attachment.htm> _______________________________________________ AMC-list mailing list AMC-list@xxxxxxxxxxxxxxxxx http://list.amc-list.com/listinfo.cgi/amc-list-amc-list.com