Doing pretty much this! Have ~500 miles so far, so barely broken in and haven't really pushed it yet...37s arrive this week. Should still be fast enough, and certainly faster than other JL options.If you do it right when you get it, you won’t know the difference!
I'd prob lean towards 4.56's - my commute has me on the highway at 80+mph daily. While this is not a daily driver, and just a toy, - there will be times I take it on highway cruises. My TJ is geared too aggressively for highway, and I'd hate for the JL to end up like that.
Not adding a lift, but adding 37" Ride Grapplers on Fuel Shok wheels (-12 offset). Installer thinks that should work for clearance. Fingers crossed!
The extra 2+’ of wheelbase a jlu has over a CJ7 kind of makes the comparison apples to oranges. Break over angle on 37’s is probably close to a CJ7 on 33’s. Factor in the much improved handling, much larger wheel openings, and the cringe factor of dragging the belly of a $75k rig on the rocks and I wouldn’t run less than a 37” tire on a JLU that sees anything more challenging than a dirt road. We wheeled our 2019 stock for the 1st year and was amazed just how mild an obstacle would cause rubbing on the skids, frame, etc. We’ve been on 37’s since august, and still drag the belly more often than we ever did in a TJ or even an XJ on 35’s. Add the fact that so many people are running around on 40’s or larger, the ruts and holes are much bigger than they were back when 35’s were considered massive. 40’s are the new 35’s.
Rubbing is fine, constant dragging go for bigger tires. The only way to improve the break over angle is more clearance. 2.5” lift and 37’s does wonders for that. The Jeep is still far more stable than a stock cj or yj both on and off road. The fact that you’re on 38’s says you already know that?
Unsprung weight increases are a huge hit. So much so, I have decided against different wheels/tires for my Rubicon. (not a 392 but same math applies)
Wouldn't lighter wheels have the opposite effect for your Jeep then? Like keep the same tires but get lighter better wheels and you will have a decent performance gain?
100%. However, the last time I looked there were no aftermarket options lighter than my factory wheels. Tire weights also factor in.
I had the same concerns. My 2018 JLUR had 37“ Ridge Grapplers and it ran and looked great. Moving to the 392, the last thing I wanted to do was kill the performance gains with bigger tires so I installed 35” Ridge Grapplers. The performance did decrease, but very slightly from what I could tell. In reality, I am not flooring the accelerator at every green light or taking it to the drag strip. Now that I have about 2,000 miles on these 35’s, I think 37’s will be totally fine even without re-gearing. The torque on this 392 is insane. The other reason I went with 35’s for now is that no suspension mods were required. Once some 392 lift kits become available, I will definitely consider moving to 37’s. I hope that helps.
