- Location
- In the islands
My 2001 XJ has had three sets of gears, the stock 3.55s, 4.10s and 4.56s.
I ran 10.50 X 31s, with a AW4 for several years, first with 3.55s and then 4.10s.
The 3.55s did not do well going up grades, which is much of the time in the West, with the engine spinning too slow in overdrive.
Re-gearing, I found that 4.10s and 31"s were perfect for both highway driving and off roading. Driving became more enjoyable and my mileage didn't change.
If you can afford it, you will not regret it.
Over the years there have been many discussions here on about the perfect gearing to tire size combination. Many of us have differing opinions as to what is perfect. I must agree though that what is perfect for some is absolutely impossible to work with for others. Opinions here is as different and varied as,....well snowflakes.
I agree 100% with the comment of Lazyxj. I ran 31" BFG's on 3.55 gears. Using cruise control on the highway with about 300lbs of cargo and just myself the AW4 would do a gear hunt on every incline. The fuel consumption would also go down the tubes if I selected 3rd gear manually. Going to 4.10 gears was the perfect(in my opinion) solution. Yes, there difference between my XJ and yours, namely,...mine have an AW4 and yours 5 speed manual. However, for highway driving both transmissions have just about the same ratio in the top gear/over drive. The differences are so miniscule they are not worth mentioning.
In conclusion, I would say choose your tire size, your driving terrain be it crawling or highway and gear accordingly. My XJ give best fuel economy between 2300 and 2800 RPM which is between 60 and 75 MPH on the highway.