I am considering a 3.90 gear. What kind of performance gain I can expect with a 3.90 gear on a stock Z on 0-60 mph and ¼ mile? 0.3 second? Also, gas mileage would drop by how many %? Will I feel a noticeable pull? Thanks.

 

All I can say is that you will feel a definite difference. The car will pull much faster.

The other questions have too many variables to answer.

 

You will better your et with 3.90's BUT if you dont use dr or slicks it may be harder to launch. Just my experience. I didnt gain much at the track on street tireswhen it was near stock, but the car was alot funner to drive.


[Modified by robz, 9:25 AM 3/16/2004]

 

When I put 4.10's in my Mustang my gas mileage actually went up!! I think it's because the car pulls out easier! You 1/4 should decrease if you hook at the line. Your MPH may go down, so don't be surprised.

 

Mid to high 11's and your trap speed will go up since you'll nail 4th earlier...and pull stronger in it. Of course all depending on traction.

 

i am thinking about gears myself :lurk:

 

If you drive on the street alot you will get better mileage , its on the highway where you will loose mileage and then there are variables. I got 3.90's in my z and i think there perfect , i did drive a 4.10 z and in my opinion a little too much as a matter of fact the 4.10s were being changed out to 3.90's ,the owner said he never used 1st gear and shifted too much. He actually let me drive his car too talk me out of 4.10's.