How can i tell what gear ratio is in my car? i think its like almost 2000 rpms in 5th gear doing 65 mph...maybe its like 1900 rpms...what would my gear ratio be?
If you were going by speed and RPM, we would also need tire diameter, EXACT speed and RPM, and gearbox ratio (5th gear ratio, which should be 0.675).
Or, the next time you change your rear and fluid, look in there and try to count the ring and pinion gear teeth. Then divide the ring number by the pinion number. I can't remember if thats real easy to do though, when everything is in place, since the pinion is kind of hidden.
Axle tag codes and door tag codes indicate factory installed rear end ratio. Tables indicating specifics are complex, and you might be able to find them elsewhere on the internet. But suffice to say, that if the door tag (labled "AX" on the lower part of the drivers side door) on your car reads "M", then its 2.73 or if its "Z" then it is 3.08.
Axle tag codes WFC-"D", "E", or "BK" indicate 2.73. WFC-"A", "C", "R", "AA" or "BM" indicate 3.08.