Of all the low drag components we offer, bearing spacers make the biggest difference. A 200-500% increase in hub free spin is common, so it's a difference you can feel just by pushing the car. However, the biggest difference is in the corners. Bearing spacers distribute the thrust load between both bearings, allowing the hub to roll more freely in the corners. Bearing spacers prevent the typical over tightening of wheel bearings, reducing drag and lowering bearing temperatures.