Hi guys, need a little help please.

I have a 6 speed manual shift 2014 v6 3.7

I am going to change the rear differential gears to either a 3.55 or a 3.73


I need insight and opinion please from those of you who have actually done this and have changed the gears in your car . -- Are you happy with your choice on your manual shift 3.7 ? - Or do wish you had gone bigger to a 3.73, or smaller to a 3.55?


Do some of you who did 3.73 wish you had installed 3.55 instead?
Reasons might be:
3.73 made it where you are shifting too much or shifting a lot more often than you care for
or it revs too high at 75 mph going down the freeway
or gas mileage suffered too much?


Do some of you who did 3.55 wish you had installed 3.73 instead?
Reasons might be it just didn't give you enough grunt and more torque, and now that you've had it a while you wish you would have installed 3.73 instead?



Thanks you all so very much for your help and sharing your experience.



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It all depends on how much highway driving you do and how much you care about gas mileage. I went from the factory 3.31's to 3.73 on my 2011 automatic. Big difference but if i knew we would be buying a new Ford Edge Limited to do 'all' of my highway trips with i would have gone with 4.10's.

Gears don't add extra power and torque, it just makes the power and torque 'peak' sooner and at lower speeds.

 

Question please for guys with * 3.73 * manual shift cars

What RPM are you going at 80 MPH, and is 1st gear pretty much useless, meaning 1st gear is over in a few couple of seconds, and you can take off from a traffic light in 2nd gear?


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I have to check at 80, but I'm pretty sure it's around 2300 rpm. 1st gear is over pretty quick, but I still generally use it 75-80% of the time. Taking off in 2nd is like taking off in 1st in pretty much any other car. You can easily start in 3rd too, which I did on accident a couple times when I first got the car.

 

Hey OP, mind me asking you what you currently have? I have 6speed manual transmission - 3.31 gears and am happy with performance output..... why are you looking for a higher gear ratio?

 

This car is a 2014 v6 manual transmission with 2.73 gears which are soooo lazy, so I am going to install 3.55 or 3.73.


I am very thankful to all of you for sharing your first hand experience with what you have found after installing 3.55 or 3.73 gears.


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I too have a 6-speed v6 mustang with 2.73 and I am very interested in this thread but I have been sold on the 3.73 gears. I can already start in second gear so I am unsure why you would have a problem. I mean you aren't going to be accelerating fast using 2nd gear starts but it is good in the rain etc. I am prepared for the MPG loss but it is a Mustang after all and I hear it is a relatively small loss in MPG and worth the upgrade.

 

Mine is a V6 with manual 6-speed as well and I am going to install 3.31 gears on tuesday. In my opinion the best choice if you want a better acceleration and an acceptable mpg average.

 

While I haven't swapped gears from 3:31 to 3:55/3:373, I can tell you that driving my wife's stock 11 GT/3:31 vs my 13 Boss/3:73 is night and day. Sure my Boss has a more powerful engine, but her GT just feels sluggish compared to mine.

Laserred was spot on, at 80 you are turning 2300 rpm. The wife is right around 2000 at 80. 6th gear on the 6MT is so tall you really are sacrificing much in MPG vs the 3:55. So if you are going through the hassle of a gear swap, *go with 3:73*.

Yes, 1st gear is pretty steep, but as mentioned, you can always start in 2nd.

 

I went from 3.31s stock to 3.73s and absolutely love the 3.73s. It's the way the car should have come from the factory. I feel like I have more usable power. 1st gear is more than usable but now you can start in 2nd too if you want to like in wet or slick conditions. I get 24mpg at 80 mph but get 27-29mpg at 70-75mph.

 

I know i dont own a v6 but i will tell you that unless you drag your Stang the aggressive rear gearing is a waist of $! A few tenths of a second is not worth it if you just daily. Down shifting is easy!!

 

I have the 3.73 in my '14 GT and a 3.55 in my '65 (which is a straight six). Yeah, I know- completely different animals. Still, I think the 3.55 would be a good compromise- the 3.73 makes a game out of how quickly I can get out of 1st, and increases RPM at highway speeds (of course, I consider highway speeds to be around 80mph ).

 

keep in mind that the v6 has a much shorter first gear than the GT. You don't have to go to 3.73s to avoid sluggishness off of the line.

 

I redline at 36-37mph in 1st gear. That's not considered short in my experience. I can get to 60 mph before I have to shift into third. 1/4 mile run requires a shift into 4th.

 

Going from 2.73s to 3.73s takes about a full second off your 1/4 mile considering you haven't otherwise modded the car. Going from 3.31s to 3.73s take around half a second off.

 

I'm upgrading to 3.73s very soon and Im looking forward to it