3.7 Gears

[Sinntax]

Looking to change out the rear gears. Currently 6spd manual with 2.73s.... 1.5 rpm @ 60 mph. from what I've seen everybody says go 3.50's or 3.73's. but I don't want to nuke my MPG either. so i'm considering 3.31's.

Any thoughts would be appreciated.

Also if you currently have a gear swap, could please post what gears you have and what RPM you have at 60 mph. would be a great help Thanks.

 

[bullitt1011]

My son has a 2014 3.7 6spd manual and he'll be going to 3.55's with a 6 spd manual you will still get great fuel economy and the car will be a comletely different ride. If you want to accelerate you'll be higher in the rpm band which makes for a far superior/enjoyable ride.

 

[86GT351]

Don't fear the gear

 

[GriffX]

You guys really need a piece of software to calculate the rpm for a different gear ratio when you have 1500 @ 2.73 ?

 

[Dino Dino Bambino]

Looking to change out the rear gears. Currently 6spd manual with 2.73s.... 1.5 rpm @ 60 mph. from what I've seen everybody says go 3.50's or 3.73's. but I don't want to nuke my MPG either. so i'm considering 3.31's.

Any thoughts would be appreciated.

Also if you currently have a gear swap, could please post what gears you have and what RPM you have at 60 mph. would be a great help Thanks.

Unless you live in an area that's completely flat, you won't see any mpg loss going to a numerically higher axle gear ratio because the factory 2.73 is beyond ridiculously tall.

The optimum axle gear ratio is a 3.27 for the 3.7 manual and 3.90 for the 3.7 automatic assuming stock diameter tires.

You guys really need a piece of software to calculate the rpm for a different gear ratio when you have 1500 @ 2.73 ?

What for? You have me!

 

[MrBhp]

Heck, I still get 20 highway with 4.10 gears and a big turbo on my 4.6.

 

[Blue03Cobra]

You guys really need a piece of software to calculate the rpm for a different gear ratio when you have 1500 @ 2.73 ?

No, but it's the same reason I use an Excel spreadsheet to balance my checkbook...rather than penciling in the ledger in the back

 

[Sinntax]

No, but it's the same reason I use an Excel spreadsheet to balance my checkbook

Check book? what's that

 

[Sinntax]

My son has a 2014 3.7 6spd manual and he'll be going to 3.55's with a 6 spd manual you will still get great fuel economy and the car will be a comletely different ride. If you want to accelerate you'll be higher in the rpm band which makes for a far superior/enjoyable ride.

View attachment 110931

View attachment 110932

Thank you

 

[Sinntax]

The optimum axle gear ratio is a 3.27 for the 3.7 manual and 3.90 for the 3.7 automatic assuming stock diameter tires.

3.31 is what I was thinking of going to, "optimum"? is this opinion or there some sort of HP/MPG formula or something?

 

[Dino Dino Bambino]

3.31 is what I was thinking of going to, "optimum"? is this opinion or there some sort of HP/MPG formula or something?

Optimum for best performance, and the 3.31 is close enough to ideal for the manual 3.7 anyway.