>>28476991Wheel spacers increase the forces on your wheel bearings and outer ball joints, causing them to wear out faster. A LOT faster with larger spacers.
Wheel spacers also change the scrub radius of the suspension, which can cause drastic and unsafe effects on vehicle handling, which vary depending on whether the vehicle previously had a positive or negative scrub radius.
If your car already has a positive scrub radius then the wheel spacer will increase it. A higher positive scrub radius will make the steering jerky and also causes the wheel to gain positive camber when the wheels are being turned, reducing grip in corners.
If your car has a negative scrub radius then installing a wheel spacer may cause bigger issues. The outward movement of the wheel can make a negative scrub radius become zero, which is the worst thing to have for a scrub radius. A zero scrub radius can cause the wheels to squirm/shudder depending on whether the inside or outside edge of the tire/tread has more grip, resulting in extremely unpredictable handling.