Title kinda says it. I can't decide between 35's and 37's and was wondering what people's experience is with the factory 4.10s while running 37's. I'm coming from Jeep world and a re-gear was almost mandatory if you wanted to see 8th on the highway. Mileage is not my main concern I'm more interested in what kind of performance hit did you notice? How is highway cruising, will it hold 8th or does it see a hill and downshift? If you've had a bad time what gears would you recommend? Thanks in advance
I'm currently running 37" Nitto Trail Grapplers on stock 4.10 gearing and stock suspension. I do have my speed-o adjusted to the new tire size.
For street driving at 50 mph or lower on relatively flat pavement, I haven't seen any difference in performance. It is mainly during a change in road grade, whether it is minor or significant, where I see a change in shift patterns.
For highway driving at 65 and up is where I do see a change in shift patterns. During long trips of 40+ miles on open freeways (early morning Los Angeles freeways are wide open) at 72+ mph, using active cruise control, I will see changes in shifting depending on road grade or if someone is in front and active cruise is adjusting to slow or catch up. A good example from today I was driving on a long stretch of the I-10 at 75 mph with no one in front of me. As I'm coming to an under pass and the road gets higher I lose a couple mph and the truck shifts from 8 to 7, then back to 8 as it gets back to 75.
At some point I should switch to 4.56 or 4.88 (leaning to 4.88) but I only travel far for wheeling and 95% of my work commute is on the street.
If you do a lot of far driving, I suggest re-gearing.