bmkj02

Hi guys,
I have a 2011 GT Automatic with 3.15 gears. I want to wake it up a little but don't want too lose much more gas mileage. Not like these cars are hybrids. My 87 Stang GT has 3.73 and is a 5spd but I hear this newer cars really isn't the same when changing the gears. What are you running and how do you like it? What do you recommend?

kanetruck

I have 3.55 gears and love it with the 6 speed stick. Somebody will chime in that knows more than me. But you can also read threads too and just use search to find them. Good luck.

Lethaldosage423

Ive got the Track package on mine so it came with the 3:73s I love them, the power is always right there. it feels strong and i can pull in any gear.
6th gear, 80mph, im doing about 2500 rpm. my exhaust is loud so a lower rpm would be nice, but its worth it in my opinion.

Slowbra302

I think 3.31 for autos is best from what I have read on the forums. Scott will chime in and I think that's what he swears by.

scottmach

The autos come with 3.15's because of the steep gears in the transmission. If you were to do the math it would come out to a 3.55-3.60 gear. Many have done gear changes with no improvement in their times. The fastest N/A autos are running 3.15-3.31 gears. The autos tend to feel a little sluggish off the line because they need two things. A good tune and a converter. The converter makes a significant difference.

bmkj02

I have been reading some of the same 3.31 gears. If I go with 3.73 will it runner slower than if I had 3.31 or the same? And I do have a tune also
Also I noticed some come stock from the dealers with 3.73 gears. Whats up with that?

scottmach

The same. It may feel a little faster but in reality it won't be.

learning

I have 3.55 and love them. Gas mileage
maybe dropped 1mpg.

KevStangZona

I have 3.55's too. It might seem quicker but that is because it breaks loose. So more than likely you will be slower unless you get bigger tires and LCA's. I just did the LCA's too early to tell but I think it is a little better. I still have the stock 235/50 r18's Have to wear some of that tread off before I go to the 19's and 275's on the rear. If your going to add any power adders then no higher then 3.55's I would think.

KevStangZona

Also if you look at the gears(3.55,3.73,3.31) on AmericanMuscle.com they have the tables comparing MT vs AT with RPM at certain speeds so you can see how the automatic compares to the manual 3.55 in the auto is close to the 3.73 in the MT according to their tables and the 3.55 table matches in my car. I noticed maybe a mile or two drop I do about 45 freeway miles each day. As long as am not on it I can still get 20.