I suppose its like asking why get an Xterra.

There are other vehicals that get better mpg, hold more people or cargo, can go faster, etc...

A 2wd SUV is kind of like a cramped minivan...and has none of the suv advantages.

The primary reason to get an Xterra should be to go places you wouldn't otherwise be able to go...its small enought to fit on Jeep trails, yet large enough to carry enough equipment and supplies, etc.

I liken the concept to buying a corvette with chevette running gear...it looks like it can go fast and handle well, but its a fiberglass chevette, not a sports car.

Buying a 2wd SUV is the same concept...it LOOKS capable, but its just a minivan.

If you want a minivan, a Honda Odessy for example is a better minivan than a 2wd Xterra.



If you want a minivan that LOOKS like an Xterra, then a 2wd Xterra is the way to go.

If you can go where you want , and do what you want to do with your minivan, you don't NEED 4wd...



If you need to be able to go more places and do more things than the minivan can handle due to a lack of traction, THEN you need 4wd to help you get there.

As for when you USE the 4wd....its whenever you want more traction in slippery conditions...there are no rules except the slippery part.

If its not slippery, the 4wd binds from too much traction on turns.

The 4wd also has a low range that the 2wd doesn't. This gives you a lower gear set for power pulling, and or slow speed maneuvering, etc. w/o stalling...and, the ability to let the engine brake all 4 tires on the way down a steep hill.

So - you can drive in 2wd until you are stuck, or better, until you see conditions that would stop a 2wd...so you don't GET stuck.



In short - except for wanting your minivan to look like an Xterra, there's really no point in getting a 2wd Xterra...and, if you Need 4wd, then a minivan's a bad choice....

And

You can use 4wd any time you want as long as its slippery.