The 3.31, 3.55, 3.37 gears that people have been talking about
 

I have a question about the 3.31, 3.55, 3.37 gears that people have been talking about.

1.) I assume they are the differential gears, right?

2.) So, the larger ratio, the better performance, but worse gas economy?

RE: The 3.31, 3.55, 3.37 gears that people have been talking about
 

pretty much, because the higher ratio the higher rpms ur turning at higher speeds, so if ur goin 70 with 331s and turnin 2500 rpm and then u put in 410s and ur turnin 3400 (these are made up numbers for the purpous of my example) then ur gunna use more gas. so yeah.:)

RE: The 3.31, 3.55, 3.37 gears that people have been talking about
 

The last gear set your thinking of is actually 3.73 but yes the numerically higher the gearset, the faster the acceleration. But your mileage will fall off a bit. I run 4.10s and average about 22-23 mpg on the hwy.
The popular gearsets for the new GTs are 4.10s 4.30s and 3.73s for autos and somesupercharged/turbocharged cars. 3.31s and 3.55s are the ratioscome in the cars off the showroom floor.

RE: The 3.31, 3.55, 3.37 gears that people have been talking about
 

There is a nifty lil gear ratio/speed calculator on here some where but for the record @ 70 in 5th I turn 2500rpm with 4.10s and about 2700-2800rpm @80mph in 5th.

RE: The 3.31, 3.55, 3.37 gears that people have been talking about
 

I have an '06 GT manual and can't seem to locate what gears I have from the factory. I've eyeballed the window sticker/ door frame sticker and can't seem to find a number for my gears. Is there a metal tag on the diff that says what gears were installed (my jeep had this).

RE: The 3.31, 3.55, 3.37 gears that people have been talking about
 

So they are the rear differential gears ratio, correct?

RE: The 3.31, 3.55, 3.37 gears that people have been talking about
 

Look on your drivers door tag. I have 3.31's and the door tag has a code of CG.

RE: The 3.31, 3.55, 3.37 gears that people have been talking about
 

Mine is listed in the options part of the window sticker.

RE: The 3.31, 3.55, 3.37 gears that people have been talking about
 

You have 3.55 gears. These are standard on 06 manuals. They are an option on 07manualmustang gt's

RE: The 3.31, 3.55, 3.37 gears that people have been talking about
 

Ya I have one of the power/speed calculators. I.E.3:31@6500rpm w/26"tire would do 152mph. 4:10@6500 w/26"tire would do 123mph, .4:56@6500rpm w/26"tire would do 111mph. Obviously 4:56 will get you to 111mph alot faster than the 3:31's These figures are with a tranny of 1 to1 final ratio. I guess you want it quicker but it depends on your purpose. Are you gonna race all the time with it? Or go on trips, or daily driver? Daily & weekend race? 3:73 are a good all around gear. Can still travel on highways without whining the crap out of it. But if your mostly gonna race and a little daily,go with 4:11. All race on the quarter 4:56. All race on the 1/8th go with4:88 or go sick with 5:13.