Hello, I have a 2003 procharged gt and I have the stock gearing. I have noticed just how lazy the stock gearing is, and I would like to put some new gears in it to liven things up, however I do not want to sacrifice too much mpg (I already only get about 15mpg and it is my daily driver). I was wondering if I should go with 3.73's or 4.10's. Would the 3.73's make enough difference to get my 0-60 and 60-100 times up or are the 4.10's just something that is necessary. Also, does anyone know what I will be paying for labor if I had a shop install the gears?

P.S. if anyone knows how much it costs or how to fix the speedometer after a gear install, please let me know!

 

4.10's are better off the line. I'd think for highway cruising, a 3.73 would be better but might not be the change you want if it has 3.55 in there now.. What is in there now?

 

I believe the stock 03 GT has 3.27's

 

I've had the best overall results with 3:73's because of all the hiway driving we do. just make your sure you match up your gear change with some sticky tires, losing traction with the extra HP can be at times can be unsafe.

 

What do I need to do to get my speedometer adjusted?

 

Unless your car is either naturally aspirated or used mostly for track duty, I would not recommend anything above a 3:73 gear ratio on a FI application, especially if your car is a daily driver. Otherwise your highway mileage is going to be less than the 15 MPG you currently have at the present. You can also expect to replace your rear tires more often as well due to the increased torque your S/C is putting down to them with a shorter 4:10 gear ratio in place. That being said, for your particular application, upgrading to 3:73 gears should provide the desired improvements for increasing your 0-60 and 60-100 times without sacrificing fuel efficiency when driven on public roads/highways as a daily driver IMHO.