* 5: This number in both refers to the number of lug nuts/bolts on the wheel. Both patterns use five lugs.
* 115: This is the *bolt circle diameter* (BCD) measured in millimeters. It's the diameter of the imaginary circle that passes through the centers of all five lug holes.
* 5: In "5x5," the "5" represents the bolt circle diameter, but this time in *inches*.
Therefore, the key difference is the unit of measurement for the bolt circle diameter: one is in millimeters (115mm), and the other is in inches (5 inches). They represent significantly different-sized bolt patterns, making them incompatible. A wheel with a 5x115 pattern will *not* fit on a hub with a 5x5 pattern, and vice versa.