Need help deciding on gear ratio

budd · Nov 7, 2014

Was wondering if I could get some ideas on what gear to go with. I've got a 97 GT 4.6 5spd, 126000 miles on it. It's still got the stock 3.27 gear. The car is basicaly stock other than 70mm tb and under drive pullies. It's not my daily driver but I do enjoy driving it as much as possiable. I'm sure I don't want 3.55's and I'm thinking 4.11's would kill my fuel mileage. I'm kinda wondering 3.73 or 3.90's? I guess what I'm asking, how much worse will the 3.90's hurt my mpg over the 373's and what rpm's be turning at 55-60 mph? Any HELP would surely be appreciated. THANK, Budd...

Dsg94sn95 · Nov 7, 2014

Can't go wrong with 3.73.. They're ideal in a 5 speed but if it was an auto 4.10s would be best

Ferocious · Nov 7, 2014

1. It's not your daily driver.
2. It's a mustang, you didn't buy it with fuel economy in mind.
3. 4.10s or go home.

joekd · Nov 7, 2014

4.10's in my 96 GT 5 speed and if I remember right I was like 2300 RPM at 65mph

chris91 · Nov 7, 2014

You're not going to see a big difference in gas mileage between 3.73's and 4 10's. The mod motors love the higher gear as well. As they say, never fear the gear.

SnakeMedic · Nov 8, 2014

Ferocious said:
1. It's not your daily driver.
2. It's a mustang, you didn't buy it with fuel economy in mind.
3. 4.10s or go home.

THIS.

g36 monkey · Nov 8, 2014

Depending on cruising speed, the difference between 3.73 and 4.10 is like 2 mpg

budd · Nov 8, 2014

thanks all of you have been very helpfull. I guess I don't have to say that I'm pretty excited about this upgrade.

D3VST8R96GT · Nov 8, 2014

3.73 will let you have a use able 1st

DeepList · Nov 9, 2014

I have 4.10s in mine and it's a 5 speed... I wouldn't consider anything else. If I cared about fuel economy, I would have bought a prius instead.

cobra head · Nov 9, 2014

for what u have I say 373 I have 410 with a ton of mods I hate them im ab to go with 355s but I have a lot of tq so its not going hurt me but it u do any kinda modding u will have to change the gears soooo I say 373

D3VST8R96GT · Nov 9, 2014

Mostly stock Gt 5spd max I would go is 3.73

Cobra 5spd 4.10s.... they have a few more Rpms to play with

Sinned83 · Nov 9, 2014

g36 monkey said:
Depending on cruising speed, the difference between 3.73 and 4.10 is like 2 mpg

no way. I just went from 3.73's to 4.10's. I can barely notice any change in mpg. I'd go with the 4.10's

g36 monkey · Nov 9, 2014

Sinned83 said:
no way. I just went from 3.73's to 4.10's. I can barely notice any change in mpg. I'd go with the 4.10's

I was saying the difference is pretty small. And depends on if you do a lot of highway or not. I do, and I would notice the difference going from my 3.73 to 4.10 right now. But in a mostly city car it would be hardly noticeable

budd · Nov 11, 2014

how much differance can I expect between 3.27's and 3.73, 2 - 3 ?? mpg's? The car does well as is but, I've been wantin more bottom end. Thank you guys for all you advice.

Sinned83 · Nov 11, 2014

budd said:
how much differance can I expect between 3.27's and 3.73, 2 - 3 ?? mpg's? The car does well as is but, I've been wantin more bottom end. Thank you guys for all you advice.

These cars get pretty good mpg it's not uncommon to hear of mid 20's. I doubt your talking a gallon even if you drive aggressive.

budd · Nov 11, 2014

Yea I've done as good as 25.8 all highway miles 55-60 mph. Combined depending on my foot I still think I'm @ 20-23. So I'm not affaid of losing a few, 3 or 4. Honestly I didn't buy it for economy but was surely suprised with it and have taken advantage of it. It doesn't do bad as is but, it's like now, I'm wantin to feel more bottom end.