I won't lie you'll surly scratch those 20's up even avoiding rocks theres limbs an what not thatll pop up an say hey when you ride over em. If you get your tires at discount tire with there warranty they'll do free replacements one time per tire then to add the warranty to the new tire its just an extra 40 bucks. (yes even if you cut it off roading). When i did my tire set up i wanted to get some nice rims but knowing what i was gonna do with them i went with the old school steel nascar rim you can beat the beeds back in with a hammer if you do any damage and scratchs get fixed with a quick spray of a paint can. I payed 97 a rim at punchy whitakers tire and wheel and then went to this offroading place called Galloways 4wd services they have a feild full of used tires after about 3 hours of plucking out all the 33x12.50 r16's and 305/70 r16s we picked the best four and grabed a lonly looking TSL super swamper for a spare payed 100 bucks for all five tires they drove like **** on the road but even after dry rotting in a feild for a few years or so they held up to the rocks better than a few new sets we past by getting plugs put in lol. I road around with them for a few months trying to save up for a new set of mickey thompsons but finally broke down and refincanced the truck for a little extra tire money lol. I bought the new tires for 1075.00 for all four 305/70/R16 MT mtz's and they've been to uhwarrie twice and preformed flawlessly. (my jeep buddies are running the baja claws an there working great on the rocks to). plus as my daily drive with about 8000 miles on them there still well below half life. My plan though is to save up for a nice set of road tires an rims an just switch out when i go on trips. (i sold the stock rims to help pay for my UCA's:dammit

Anyways i was gonna say if you dont have the large front brake rotors and you want/can to run a 16" rim i still have all those used 305/70r16's you can use them if you wanted to pick up a set of cheep offroad rims to mount them on. You could def throw down without worrying about those nice 20's. I may be making uhwarrie sound like a tire grave yard although this has been my experience i would sum up most of it to be caused by A.) our crazy driving offroad B.) all the used ass tires we've tried to run to save money on new tires lol. All the guys running newer 6ply mud tires have no problems aswell i havent had any problems since i got my new set. I def. recomend atleast a 2ply sidewall, lets you run lower pressure an still have a load rating plus it fights off those rocks that like to poke at ya when you drive by. def. look forward to getting out there with another 4th gen!! I cary two spares plus if you have any we would certainly be prepared!!
I will say uhwarrie has been my most favorite place to offroad, the park connects with baden lake so if you have a boat you can spend a weekend real easy fishin, rock crawling, mudding, skiing, wakeboarding, even horseback riding if you bring horses, the works. As well theres a country store at the entrance to the park that has an awesome air compressor (it askes for coins but theres a switch mounted behind the coin dispense for locals who know how to get free air.) plus the store serves breakfast lunch and dinner serving up sausage, bacon, eggs, grits, hashbrowns, biscuits, fried chickin, burgers, chicken wings, and they sale, antifreeze, distilled water, oil, tire slime, towing equipment, tools, camping goods, just about everything you need in a pitch. To add to the benefits albemarle is maybe a 20 minute ride an has a autozone. advance auto, and i believe an orielys autoparks. and a walmart if your in dire need of a new tire to get somewhere on a sunday!!lol.