hey i was just wondering if i picked some 3.73 gears and put them on a stock 95 a4z if id notice any difference? thanks

 

Yes, you would notice you had different gears. You would notice more torque multiplication. You would notice that you need to have your PCM reprogrammed for the speedometer to read right and the transmission to shift correctly. You would notice that your engine revs higher than before at the same speed. You would notice if "feels" quicker (but it actually might not be in the quarter mile). What in particular do you want to notice?

 

And, what gears do you have now? The A4's came with either 2.73's (GU2) or 3.23's (GU5)? You're looking at a 15% increase in rear wheel torque multiplication if you currently have 3.23's, and a 37% increase if you have the 2.73's. You'll definitely "notice" the change form 2.73's. Might notice a decrease in fuel mileage as well.

Check the build code tag in the glove box for GU2 or GU5.