# General Maintenance & Repairs - Can someone calculate how many miles my car really has for me?

eb2phkingood
07-09-2012, 03:19 PM
This is for my own personal knowledge. I have a 1 owner trans am. (own 4 trans am's total). This one specific trans am came with 3.23 gears. After 16 miles on it, I switched it out to a racing gear 4.56 and have drove it like this ever since. In fact, I made it a daily town driver as it actually got great gas mileage with that rear end helping it take off. My question is, this car is at 62,287 miles right now. It has always read off on the speedometer and odometer. I just yesterday put a diablo on it to fix the gear and speedo. Can anyone tell me how many miles my car actually has on it for peace of mind?

Cliffs: 4.56 gears since day 1 say 62,287 miles but the computer thought I had 3.23 gears all this time. So how many miles do I actually have on this car??

FirstYrLS1Z
07-09-2012, 04:09 PM
4.56 / 3.23 = 1.412
62287 x 1.412 = 87949

aren't 4.56s' in an autoA4 great,I ran them for 4 years and just recently switched back to the OEM 3.23s'. I MISS THE 4.56s'.

predatorz28
07-09-2012, 06:53 PM
Wouldn't it be 3.23/4.56? With the taller gear, one revolution of the driveshaft means less turning of the wheels with 4.56s vs 3.23s.

3.23/4.56=.7083
62287*.7083=44,120 miles

FirstYrLS1Z
07-09-2012, 08:37 PM
I stand corrected,you're correct. I was figuring engine use because of higher rpm.

SVTconfused
07-09-2012, 08:50 PM
no wonder it got good gas mileage....

FirstYrLS1Z
07-10-2012, 06:55 AM
My 4.56/A4 gave me 21.5mpg at freeway legal speeds.
The higher numerical gearing gives the engine a better mechanical advantage over the vehicle which in turn means less engine loading. As engine load changes so does the air/fuel ratio. Wide open throttle put the highest load on the engine and the computor richens it up. Freeway cruise-control with 4.56s' has a very low load on the engine and the computor causes a leaner condition,but still within factory parameters.