As the vehicle turns, the front and rear axles follow a different arc. When this occurs, the only place to compensate for this binding is between the contact patch of the tires and the ground. Even if the vehicle is driven in a straight line, there are slight differences in tire circumference (due to load, tire pressure, wear, build variances...) that will cause some driveline binding. If a vehicle had the exact same size tires and was driven in a perfectly straight line, the fact that more parts are moving would mean that there would be more noise and possibly some feel of the system operating.
Use of 4WD is intended for use on a low traction surface such as snow, mud or sand. On a low traction surface, the differences in front and rear axle speeds will not have as much effect on binding because of the lower traction levels between the surface and the contact patch of the tires. On a high traction surface, the higher traction levels will create more binding and noise in the driveline. This might make the ATV/UTV harder to steer, turn and lead to premature wear of components.
Last edited by Z71; 02-18-2013 at 07:35 AM.