When choosing an offset for an aftermarket wheel, it is important to take note of the space between the outer edge of the wheel and the fender. Depending on the desired style, you may want to match the change in offset from stock wheels to the amount of space between the wheel face and the fender. For example, if there is 15 mm of space between the outer face of the wheel and the fender and you're wanting a flush fitment, you would want to go from a +45 mm offset to a +30 mm offset. This will bring the mounting surface of the wheel further inward towards the vehicle from the true center point of the wheel thus poking the wheel out by an extra 15 mm.