Have 95Z28 A4 . Why is it that 3:73 gears are recommended for Automatics and 4:11 for 6 spds.? If I put in 4:11's in my A4 what is
the downside?

95Z28LT1A4 Red w/black Ttop. 58mm TB/Racetronics fuel system,
full race suspension/ Spohn A arms/Kmember, MSK etc..too much to list

 

One reason is that is that an M6 has a 0.50:1 top gear. A 4L60E is a 0.70:1 (if memory serves). But more importantly, if you have a high stall converter, 4.11's plus the combination of 3.06 first gear of the 4L60E and the torque multiplication of the converter gives the car too much torque to launch effectively. Makes wheelspin very har to control.

Rich

 

The downside is your rpm's on the freeway will be higher but if you don't care go with them. You lose something like 10 mph's off your top speed.

 

They are recommended that way because it is the best compromise between performance and street drivability.

 

Well, other than lower E/T's, none .

Don't fear the gear .