[DesertMK4]

Most MKIV owners use the bottom of the main frame rail to the ground as the measuring point. Most also set that distance at between 4 and 6 inches at the rear. I have used 4 1/2 to 5 1/4. My wheel size is 17 inches. A lot more of the difference comes from tire size. I would go with better ride rather than having 3/4 inch more or less gap at the top of the tire to the wheel well. Fronts are about the same, with higher settings to increase the tire to wheel well gap when the front tires are turned to full lock.