I've got a 99 M6 that's a daily driver and the next thing I was plannin on buyin was a new gear. I've rode in a car with 4.10's and I do a lot of highway drivin and don't wanna be runnin down the highway at 5 grand or so. I want to add a little more pull but without sacrificin much top end speed and gas mileage. I was curious as to whether anyone has put a 3.73 in an M6 and if so how they liked it? Do I need to go with that or just save the money and put it other parts? Thanks for the input.

 

For what it's worth I had a T5 with 3.73 and it would run around 2500 at 65. With the added overdrive people say it will be around 1800 at 70. I have heard of A LOT of people with the T56 and 4.11 gears being very happy on the highway. You shouldn't have a problem.

 

i have them in my car and couldn't be happier. It is almost a happy medium for racing/dd, not too much, not too little.

 

Just for reference...

Stock A4 w/ 3.23s

Drive Ratio in 1st = 3.06 x 3.23 = 9.88
Drive Ratio in 4th = 0.7 x 3.23 = 2.26

M6 w/ 4.10s

Drive Ratio in 1st = 2.66 x 4.10 = 10.91
Drive Ratio in 6th = 0.5 x 4.10 = 2.05

There's no reason not to run 4.10s, it will give you about 20% more torque off the line, but you'll still be running less rpms than an auto on the highway- somewhere about 2k @ 70 if I remember correctly.

 

Im going with 3.73s so i dont have to shift into 5th gear in the 1/4.

With a 27'' tire 5700 RPMs is 123 MPH, with 4.10s its 112 MPH

I realize i wont be shifting at 5700 RPMs, but thats as high as the calc goes and with a 150shot id definetly have to shift into 5th with 4.10s

And its not like my M29 dosent give me enough torque off the line

 

the only thing bad about going to 373 gears is the fact you won't get much performance out of them. You might not even feel a difference in acceleration. I was averaging 2-3 tenths better with my 4.10 over the 3.42 gears, and thats with a better 60ft time as well. so I don't think you'll pick up more than 1-2 tenths with the 3.73's Those gears will be 100 rpm more over stock, and the 4.10s will be 300rpm over stock, so at 75 mph 1800rpm/3.73 and 2000rpm/4.10s at 75 mph. Personally I don't think its bad unless your exhaust is super loud, that would be a good reason not to get higher numeracially gears.

 

I've got M6 and 3.73. I love the combo. I like it enought that after i blew the first set of 3.73, I put another set in. That was just over a month ago BTW.

 

you wont feel a difference? I sure did and my car only has intake/exhaust.

 

4.10's

I couldn't be happier, 72ish mph at about 2000 rpm's.

 

3.73's here and I love 'em. Then again, my car was a stalled auto so that's why I chose the 3.73's to begin with.

 

I've had both. I like the 4.10's better. No problem cruising with the 4.10's in 6th gear

 

With 4.10's on an m6, you will not have to shift into 5th. If you had 4.56's, you would have to go to 5th right before the finish line. Even with a 4.30 it is very possible to stay out of 5th. If 4.30's were more available, I would get a set. However, I found a set of 4.10 motives for $55 shipped last year and I'm about to install them to replace my 4.11 richmonds which have been whinning like a mother ****er for a few months. I can't stand it anymore.