I'm sure this question has been asked a thousand times, but I just bought a '99 Cobra (Electric Green Convertible) and obviously as much as this DOHC loves RPM's I need lower gears. Just curious as to what others prefer for the street. 3.73 VS 4.10. I have also considered 3.90s. I know that most will say 4.10's for racing. This car won't be raced, however, it won't be a daily driver either. What is your highway cruising RPM w/ 3.73s or 4.10s. What is your difference in fuel economy vs the stock 3.27s? Thanks for the help!

 

my 99 i had both , i had 4.10s at first , when 1000 miles later a swapped them for 3.73s.thats my 2 cents 3.73 got 24.5 mpg on interstate. 3.73s at 90mph=3000rpms , 4.10s at 82mph=3000rpms. i drive faster than the limit, so i like less gear. the 4.10 just didnt seem to have any pull to them also.

 

So you're saying that the 3.73s feel like they pull better than the 4.10s?

 

yes on street tires, the 4.10s just revved out real quick ,around a corner you got to shift to 2nd. before you straighten in out. cause the 99 cobra has a very low 1st. gear in the trans 3.37 ,to a 03 cobra which has a 2.66 1st gear. if you got some good sticky tires? and dont drive over 75mph in interstate for time peroids of time go 4.10s then.

 

Nothing less than a 4.10 gear on a 99/01 Cobra...these cars LOVE rpm's most 99/01 owners don't even consider less than 4.30

My .02

 

well i have a 3:73 and it launches pretty hard. I also have a 4:10 in my 91 gt with a vortech supercharger. The 91 runs side to side with my 99 cobra. I guess cause the cobra has more rpms. If i had 4:10s in the cobra it would probably pull in front of the 91.

 

not much diff. in mpg for me 4.10's here

 

nothing less than a 4.10 that is what i have and most people that you race will have to play catch up!

 

4.10s will eat up 2 mpg more on highway

 

I think that you have some good info on what the RPMs will be, and what the MPG will be... So, I will just add my 2 pennies in and say that 3.73s are just about perfect... You still won't have much of a first gear with them, but at least you are not reving the **** out of your engine when you are on the highway... In the city, the 3.73s make 5th gear more useable, so your overall gas milage won't be all that effected... Remember one other thing that I will add here--- Revolutions wear the engine out faster then anything else... If you really want to make some HP and at some lower RPMs, look at the KenneBell website and buy a nice little blower for your car. They make great power even with stock gears with the power coming on at way lower RPMs then other blowers... Just some opinions and options... Here is the Kenne Bell website: http://www.kennebell.net/index.htm