Originally Posted by Jeremy.baker
So i have searched for this but i have been without luck. I am wondering if anyone can give me some first hand experience with how much your MPGs drop when changing to a set of 3.73s.
When I had my Automatic 06, with the factory 3.31 gear I was getting surprisingly about 21 MPG. However, I had an x-pipe, cat-back, intake, throttle body, and a tune, all which help fuel economy. Once I switched over to a 4.10 gear my economy dropped to about 17 MPG.
With all this being said a lot depends on your driving conditions, habits, modifications, and current gear ratio.
If I had to guess, once you go to 3.73 you would be somewhere in the 17-21 average MPG. Normally you drop about 2-3 MPG from you current MPG on the highway. In town, I would not expect the number to be any different, as it will require less power to get moving.
This is an extremely popular mod for most people and they find it worth the minimal MPG lose. A 3.73 will be a fine daily driver gear if need be and still provide great performance.
Also keep in mind if you do want to order a set a gears we do price match, and forum members get a 6% percent discount.
I hope this helps, and by all means if you have any other questions please let myself or our customer service team know. Good Luck!