depends if you are having problems. stay with OEM (usually 10). tuning front end requires a combination of spring rates with fluid viscosity. heavier springs combined with lighter oil is great for very tight corners. it all depends on what you trying to accomplish. if theirs no problems, then don't change it. if you are bottoming out your front end, then go heavier, not lighter. lighter oil will make the front end more bouncy (requiring more compression/rebound adjustment).