Well, I just bought the car. A downside I am finding is that the guy who bought it can't recall or doesn't know what the prev owner has done. From what I have searched and found my calculations show I have 3.73 gears. I researched because I was on the highway at 70mph and I was at around 2400 rpm's (If I am wrong about the gearing please let me know). I have 275/40ZR17 tires. The car came stock with 3.23's

My question is are these upgraded gears good to have on a DD? I have noticed that my MPG's are not the greatest, but I didn't buy a Z for MPG's. Other than that what are the benefits of the 3.73's. Thanks.

 

Sounds like 3.73's - great gear for an A4.

 

Are the 3.73's good to have in a DD? I'm just trying to get some feedback on driveability and reliability of the rear end for my DD.

 

They say 3.73s are the optimum gears for an auto for street and strip. For better mileage you would go 3.23 or 2.73. For better acceleration you would go 4.10s.

I hear generally that 4.10s are the "problematic" ones, not the others commonly used.

 

i have the same tires ,373 gears and at 70 mph I,m at 2600 rpm.

 

I was gonna say that my 3.42 car is right around 2400rpms.

 

www.f-body.org/gears/ Calculator lets you plug in different gears.

 

If I put in 3.73 the calculator says at 2400 rpm it should be at 70 mph. So I guess I do have 3.73's.

 

You have 3.23 gears.

I have the same setup in a 1994 Camaro. Previous owner says he had 3.73 gears in it.

I was turning the same RPM as you, too. Today I popped the rear cover to change out the lube, and found out that I have a factory, untouched 3.23 rear. The ring gear has 13.42 stamped into it, and that's the pinion gear teeth / ring gear teeth count. That's 3.23:1.

Needless to say, I'm a bit ticked off.

 

I don't know what to think anymore. I wish there was a Camaro guru here that could take the car for a day and tell me exactly what has been done to it.

As far as the gearing, I guess I'll have to jack her up to find out for sure. I just think that 2400rpms @ 70mph is a bit high for a 4 speed auto w/OD. Of course this is my first F-body.

 

I was under the same impression until I popped the cover off to change the lube and saw the numbers stamped in there. Then, because I didn't want to believe what I was reading, I turned the wheels and counted pinion rotations and watched it go around 3 1/4 times.

Really want to know? Jack the car up and open the cover.

 

You have 3.23s dude. my car has 3.23s and its at 2400 at 70.I want 3.73s myself but dont want less gas mileage at this point.

 

Well I will jack her up and find out for sure. Thanks guys. I'll let you know what I find.

 

Or just do 70mph and put it in 3rd and if you're doing ~3700 rpms, you have 3.73, ~3200 and you have 3.23s

 

Your tach might be inaccurate. It's a common issue with F-bodies for the tach to read high.

You can check this with any ODBII scan tool. The digital RPM readout you get from the tool is always accurate -- it's just the gauge on the dash that's the problem.

If it is accurate, you have 3.73s. If not, just do the math again based on your real RPM.