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? about gears

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Old Apr 16, 2010 | 05:21 AM
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Superwes98's Avatar
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Default ? about gears

ok i want 3:55s for my gt but it seems not too many people run those so they r more expensive and no one has them lol
but how much of a difference is there in torque and gas mileage between 3:27, 3:55s, and 3:73s?




and my car is my DD so thats why i want somewhat decent gas mileage
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Old Apr 16, 2010 | 05:55 AM
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Can't tell you the torque difference but the difference in rpms from a 3.55 and 3.73 is about 150rpms. I'd go 3.73's. If your gas mileage goes down it won't be due to the gears...it'd be your foot is now more in it cause its more fun!!!
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Old Apr 16, 2010 | 09:26 AM
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Don't fear the gear. I have had multiple customers with late model automatics install 4.10 gears and report 2-3 mpg increase in the city. I would recommend a minimum 3.73 for just about anything, 4.10 preferred.

RPM and torque changes are simple percentage, and easy to calculate.

4.10 (new gear) / 3.27(stock gear) = 1.254

1.254 * 2000rshared_pm = 2507rpm

1.254 * 2100ft/lb = 2633ft/lb (wheel torque)

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Old Apr 16, 2010 | 10:12 AM
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What trans do you have now?
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Old Apr 16, 2010 | 02:02 PM
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I was where you are, weighing the difference between 3.55 and 3.73 gears - about 6 months ago. Now I had stock 2.73's behind a 5 speed. After the change - its all good, and like someone said - my miles per tank is even or better now. I use fifth gear way more often. Today I was passing a car in light traffic and got to 90mph quick and it was gettin' good, but I let off. The only thing I miss is my car gets to 4800 rshared_pm so quick you don't get to hear the exhaust for very long. To me the exhaust tone is best between 3000 and 4000.

Gears are good.
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Old Apr 16, 2010 | 03:27 PM
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I've run both and they both have good reasons to run.. Personally, more of a daily driver if it's a fox body 5 speed I'd say run the 3.55's as it still pulls hard on the street, don't have to shift out of first so quickly (and often if you get in stop and go traffic), and if you throw a little nitrous on it, it helps you on the top end.
If it's a 4.6 I don't think you can run enough gear LOL. higher the number (lower gears) the more fun the 4.6
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Old Apr 16, 2010 | 07:25 PM
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well i have a 92 GT 5.0 with a stock T5

and i do just as much highway driving as i do in town. so im kinda lookin for the happy median
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