blake79

I have a 2013 Mustang GT automatic and that I am looking to change the stock gearing 3.15's to something like a 3.31 or 3.55. However, I also drive on the highway from time to time for long trips. My question is, cruising around 70-75 MPH, what RPM am I sitting at in both ratios? Right now, around 78 MPH I sit at 2,000 RPM. I'm really looking for some extra grunt, but also dont want to kill my highway mileage. Thanks!

proeagles

Without using a formula, off the top of my head, I'd say about 500 to 700 more RPM with a 3.55 which is the normal Ford upgrade.

JimC

You are in the wrong section. The purpose of this section, as stated at the front is:

It isn't for questions about your car. It is to discuss rumors about what Ford is planning, or concepts and 'mules' that you may have come across.

blake79

Alright...I posted here because it said discussion. Where should I post this?

JimC

There is a section for every platform. You have a 2013 so you go to the S197 2013 model year section. (2005-2014).

If you do a search in that section you will probably find your question is already answered.