Look at it from the implict benefit from regaring your diffs not just because you have to regear because you're expecting to bump the performance or convienence onroad or offroad independently. It's tacit, when you need gears you regear to restore the missing torque leverage lost because you went with bigger tires, or because you want to bump that leverage a bit more and doing so affects all transfer case mode as it's all connected: engine torque, trans gear ratio, transfer case ratio, diff ratio etc.Roger, thanks guys! So regearing would be both a performance and a convinience factor when offroading. 4lo would be limited to some specially tricky spots or sections, right?
I remember when i did 35's on my 1st JK with the factory 3.21's, I didn't feel that much of a difference driving on flat roads, sure she was a little more sluggish but it wasn't bothering me one single bit, that all changed when i added hills to my conmmute as she was really struggling to go up and i had to use 3rd gear manual (auto trans) to keep the speed at 65mph. Offroading in 4lo was also bad as i couldn't feel the torque multiplication at all so things like going downhill was not controlled at all and i had to ride on the brakes like crazy to hold her back going downhill. Regearing restored everything i had lost in the performance department after adding 35's for both onraod/offroad.
You'll know when to use 4lo cause even in 1st gear you'll feel the motor struggling if your transfer case wasn't multiplying your output torque to the wheels. typically you'll need it in heavy sand, heavy snow, heavy mud, going uphill with ruts/rocks etc, going downhill when you need to torque reduction to keep the vehicle under control etc etc. you use 4hi when the conditions warrant 4 wheel drive but don't need the extra torque, so for example going to the grocery store on a snowy/icy day when trying to drive in 2hi gives you lots of rear wheel spin so you pop the TC in 4hi and now you can drive in a more controlled manner.
Hope it makes sense.