I know there's an option that ford gives for the 06+ Mustang GT to have a 3:55 Rear axle with limited slip. Stock they come with 3:31 gears apparently from ford. Does anyone know if there's a way I can decode a vin# or something to find out if it comes with the 3:55 rear axle? I'd prefer to have limited slip and 3:55 gears would be nice since I don't plan to go above that or 3:73s really

 

the pumpkin usually has a tag on it that says what it is

 

First for 05-06 all Autos are 3:31, MT are 3:55. For 07 they dropped the MT to 3:31 with the 3:55 as an option.

There is nothing in the VIN that will tell you about the rear gear. It can only reveal the body line, body style, engine and restraint system, that's all the room there is.

 

well if your an auto, the best gear it sounds like is the 3.73, it sounds like the 4.10's are a little too much for the auto but great for the manual. So I took the plunge and bought the 373 this week from johnbleakleyford. Great prices on ford racing stuff. Good luck

 

Thanks for the help guys! I'm looking pretty much for only an 06GT. 3:55 gears would be perfect for myself. I'm not into drag racing so I don't need 4:10s. Although I would like the occasional track run

 

thats cool , just thought i would mention the gears, since you were talking about the factory gearing. wasnt sure what you were trying to accomplish. good luck getting your car. you will love it.

 

Crawl under the car and look at the differentical case cover. It will have a sticker that says "3.55"

 

Thanks

 

+1... If it's an 06 GT 5 speed then it has the 3.55... 07s have the option for 3.55...

 

Any Idea why they may have reduced the rear gear ratio?

 

My guess would be mileage. (CAFE)

 

They reduced the ratio for better gas mileage. I did a cost benefit analysis and the 100 RPM difference in 5th gear wasn't going to make a big difference. I do not plan to change the ratio, so I paid the $87 for the factory 3.55s

Here's a pic of the axle tag on a 07 GT.

 

Fuel economy? Also, I think all GT's have the limited slip axle, no matter of the ratio. Correct?

 

I was thinking for gas mileage but Fun > MPG hehe

 

Soley to conserve gas...

 

+1. One of my friends (who drives a prelude) saw that the stang was averaging 15.1 MPG... he said something about crappy gas mileage. I dropped from 5th to 3rd and ran to the top of 4th... He laughed a little and all he said was "Wow".

 

If I were concerned about mileage I would have bought a Corolla. Since I have a MUSTANG, in went the 4.10s

 

15? What do you normally get? Rev much?

What would be the MPG difference between 3.55 and 3.31?

 

I'm lucky to get 12 around town

 

Check your door tag on the driver's side under axle code, if the code is CD ? it's a 3:55 hope this answers your question..