My man. Much better.I apologize for not being more specific in my question. 6th gear is purely intended to be overdrive. I would never expect it to accelerate quickly in 6th regardless of tire size. I would also expect 6th to be pretty useless on hills that most would consider steep.
I guess I could have explicitly asked "will it hold speed (70-85mph) with light headwinds (10-15mph or less) on normal interstate (non "steep grade") hills.
I do like the gear ratio tools and dyno charts, but I'm not enough of a gear head to know when it will have enough power to hold speed at certain RPM levels. According to the Gear Ratio calc tools 35" tires with 4.10 gears at 2500rpm will result in a speed of 86mph. Ok, but does it have enough power to hold 2500rpm with 35" tires?
My wheels and tires will be XD137 FMJs 20x9 ET0 with Cooper Discoverer STT Pros 35x12.5 R20.
The only thing I have to compare too right now is my JK and my memory of what it was like when it had the stock 3.21s. It would barely do 80mph. Granted 3.21s is a LOT higher than 4.10s, the JK 6spd is geared lower than the JL, but not that much lower. Knowing this I expect the JLUR with 35s won't be as bad as my JKU Sahara on stock 3.21s, but is 6th gear on a JLUR useable as a pure overdrive in the real world, or will it not hold speed in most cases?