gt2allstar

Hi everyone,
I am going to be purchasing an 09 mustang GT Premium here in a couple days and wanted to get some opinions about the 3.55 axle ratio. What exactly are the advantages and disadvantages of adding this option? Will I see better acceration and performance or is this an option for the modder? I do plan to do engine work in the future when I get more money. Intake, headers, exhaust, cams, etc. What do you guys recomend? Is it worth the 250$? Thanks everyone!!

Riptide

Better acceleration over the 3.31 default. Slightly worse gas mileage.

Most people around here upgrade to 3.73 or 4.10 gears. I have seen a few with blowers stick with the 3.55. Most do not.

GeritGoul

no tell em to put 3.73s on...if not then get the stock and add 3.73s, im pullin a half second on my mothers 07GT vs my 08bullitt

Nuke

I have the 3.55's and do a lot of long distance highway driving. I suspect I may have lost about 1 MPG over the 3.31's but the 3.55's are superior out of the hole. If I did more street driving and occasional track I'd have gone with 3.73's.

Even at 70 MPH (roughly 2100 RPM) I average 24 MPG. It goes up to 25-26 at about 60-65 MPH (hand calculated, station-to-station).

I recommend 3.73's if you're not doing much if any highway driving.

gt2allstar

3.55 is the only option they offer besides stock. I see i can get either 3.73 or 4.10s online for around 180 vs paying 250 for the 3.55. The only bummer there is the install costs to have someone do it. I am not looking to drag race with this, but the extra toos back in the seat would be a good time. Not to mention show off to my friends every now and then. Would there be a noticeable difference between the 3.55 and the 3.73? I just dont want to go way overboard cus this will be an everyday driver car not a drag racer. Also most of my driving is none highway miles. I live out in the country away from all the expressways. There will be some high speed back road driving though

ChromeDome

I would agree with Nuke as well, I had a S-10 with 3.73 Locker diff before my 09 GT and it was a real pig on gas on the highway luck if it got 19 MPG most of the time. 3.73 will pull a lot better from a light no doubt but the 3.55 seems to be a nice balance of off the line and fuel economy.

GeritGoul

yeah go with the 3.73...i do some highway ridin to work and im still gettin 22-24mpg(to work atleast)...just dont let anyone talk you into the 4.10s for your kind of driving..and yes there will be a difference! they are badass, i could just be cruisin to work or wherever just fine and if someone pulls up next to me i just drop a gear a let her ripe

gt2allstar

If the 3.55 improve the hole shot does it end up hurting it later on the top end or does that stay about the same?

Hufenstang

the car doesnt have enough power to top out the gears in the car, wether is be 3.55 or 3.73, the drag of the car will slow you down before you run out of gear.

Nuke

I find my 3.55's have plenty of top end. At 110-120 MPH, she still wants to keep pulling.

PM me with your e-mail and after I get home from work tonight I can e-mail you some spread sheets that let you plug in gear ratio, tire size and tranny type to give you RPM's for each gear up to redline.