Page 1 of 1
5th gear RPM to vehicle speed
Posted: Sun Jul 16, 2006 2:03 am
by thefultonhow
So the VSS crapped out on me in South Dakota and I now have no speedometer. My tach still works though. Does anybody know what RPMs correspond to the following speeds?
65 mph
70 mph
75 mph
80 mph
Thanks.
Posted: Mon Jul 24, 2006 4:44 am
by wiscon_mark
3.9 FD?
65=2775ish
70=3000 on the head
not sure about the others, don't drive at that speed.
I'd assume 80 is about 3500 though.
Posted: Tue Jul 25, 2006 12:42 am
by evolutionmovement
If 70 = 3000, then 1000 rpm = 23.3 mph. Divide speed in question by 23.3 and multiply by 1000 and you have your rpm. However, I'm not sure 70=3000 is correct. I have a 3.7 and I do about 27 mph/1000 rpm. Seems like a larger difference than it should be to the 3.9. 5th gear is .7xxx. I'm too lazy to look it up.