I have a 2015 f150 with 5.0, it had 265/60/18 (30")with 3.31 gears. I put 305/55/20 (33.4") tires. Thinking about swapping out the 3.31 gears to 3.73 or 4.10 gears. I drive 90% on the road. Put around 750 a week on truck. Plus I pull my 8100 lb camper sometimes. I lost around 2 mpg when I put the bigger tires on. Looking to see if anyone has done this and what's the outcome. Thanks

 

Go with 4.10/4.11.

Get a custom tune to maximize the change and adjust speedometer and tires anyway.


Expect to pay ~$2000 for gear swap if you're 4WD, half that for 2WD. And $400ish for programmer and tune. Truck will drive and tow a lot better.

 

Thanks. I called Ford racing today and they told me the same thing.

 

https://tiresize.com/gear-ratio-calculator/

 

Go to a reputable 4x4 shop whose primarily business involves gear swaps over a shop/dealer that whose is to do oil changes.