I recently bought a 2001 Pathfinder 4x4 (link) and took it to a local easy trail called Holy Jim on the very first weekend I had it. It was fun but on the scale of 1 to 10 I would rate it maybe a 2. Ever since then I've been itching to take it to a more challenging trail and see how well it does. Unfortunately the California section on Expo has been quiet lately so after patiently waiting for a trail run to happen I decided to take matters into my own hands and posted a trail run myself. Unfortunately, however, due to the short notice I couldn't find anyone available to go with me. As much as I prefer to go into the back country with others I would go alone this time. The trail has a few different names but the main section is called the North Main Divide Rd (http://www.dirtopia.com/wiki/Main_Divide_Road) and I would rate it as a 4 to 5 on the 1-10 rating scale. It has a few challenging sections but overall fairly tame. To me this is a great trail to explore the limits of a stock/new SUV.
So me, the gf and the dog set off around noon, we went up Ortega Hwy and then came down N. Main Divide Rd. The trail was about 36 miles total and it took us 3.5hrs with several stops along the way. During the 3.5hrs we only saw two XJs riding together, two dirt bikes that passed us and one badass (crazy?) dude mountain biking alone in the middle of nowhere. Needless to say we had the whole area to ourselves on this beautiful Sat afternoon. The weather was a bit warm at about 87F and the ScanGauge showed the air intake temp to be 145F most of the way. The BIGGEST mistake I made this time was deciding to drive with the windows down...NEVER AGAIN!!!! I don't know how people drive like that when I see them on the trail or in the pics. I did it so we could enjoy the fresh air and help the truck by not using the a/c in the hot weather but the interior got plastered in layers and layers of dust. My gf joked that I'd need a shovel to clean the interior- it was really bad.
For the most part I drove the trail in 2WD except when there were a few steep climbs where I didn't want the wheelspin to tear up the trail. I also had to engage 4-Lo in a couple of places, again to allow an easier climb up a steep section but I would say in this weather a 2WD with at least 8.3" of ground clearance should make it but I wouldn't recommend going alone in case you need a yank. With my stock SUV I was worried about the ground clearance over the bigger rocks strewn all over the trail but I drove slow and chose the lines carefully i.e. drove up and over the bigger rocks as opposed to straddling them so didn't scrape any metal bits at all. I was also a bit concerned about the tires (Toyo Open Country A/T) because the rocks were jagged, pointy and sharp. I was regretting lowering the tire pressure early on and several times thought about refilling them back up to 30psi so as to not tear the sidewalls on these rocks. But we kept pushing on hoping the trail would get better which it did but it took a long time to get to a slightly more forgiving surface.