The rim size isn't the issue, it's the tire size. Why would you want to change the tire size, especially with a brand new vehicle? The speedometer would read incorrectly, as would the odometer and the ABS brakes would not function properly.
You have brand new vehicle and you are changing rim if you are converting to alloy rim so its ok otherwise do not change the tire size because it will effect on road grip performance and brake system also.
