SCCX just went on a run which we wound up going through a canyon with rocks. Every one was 4x4 except for the 4x2 tacoma, he even had lockers and I will say he did awsome. However there are some situations where a 4x2 hasn't a prayer. Soft/deep sand, a stock 4x4 with open difs had absolutely no problem, toyota got stuck if he didn't have momentum and wasn't on a hard surface. Also with a 4x4 the power to the front wheels will actually lift the front of the truck on top of the obstacle, and without momentum a 4x2 won't be able to get up something that is too tall, regardless of travel.

I'm sure you can tell that I'm talking about recreation here, There is 0 need for a 4x4 here in Santa Barbara, CA but I still wheel at least once a month, but I was in Big Bear, CA and I was sure glad to have a 4x4 there, yes a 4x2 would have worked, I just would have needed to be more carefull.

But the short answer: If you're asking the question then the answer is no, you don't need a 4x4, you would know if you did. But if you wanted to go offroading then yes I would highly recomend getting a 4x4.