I agree with what CW said, but just want to point out one thing to diffuse the confusion before it starts.
In 4wd, you still send an equal amount of power to rear and the front. So you still have to be turning two tires. It can't just send all the power to one. It might be both lefts, both rights, or one of each, but the combined speed of the front tires have to equal the combined speed of the rear tires.
Unless you have a 242. But wheeling in full time isn't exactly a good idea.