I really don't know anything about tires, but from what I have learned on here and the Jeep forums, it seems like for sand you want something as wide as possible, and nothing aggressive. you want to be able to "float" on top of the sand and aggressive tires, and narrow tires would help you to dig in. The 4runner comes with decently wide tires (wider than my wrangler's stock tires) and they are not aggressive, so I would think they would perform pretty well. If they aren't working for you, try airing them down before you give up on them. Remember on sand you need to keep consistent throttle, don't use the gas more than you need to, pretend you are trying to save gas.