🔩 Shock Oil
The fluid inside a shock that controls damping. Thicker (higher weight) oil resists movement more; thinner oil moves more freely.
What it actually does
Shock oil controls how fast the suspension is allowed to move. Springs decide how far the car compresses; oil decides how quickly. It is the difference between a car that settles smoothly after a jump and one that either pogos or packs down and refuses to extend.
In practice
Oil is quoted in weight (wt) or centistokes (cSt), and cSt is the more reliable comparison because weight is not standardised between brands. Thicker oil slows the suspension: more control on smooth tracks and big landings, less compliance over choppy bumps. Thinner oil does the reverse.
Worth knowing
Bleed the shocks properly when you rebuild them — trapped air makes damping inconsistent, and a car with one aerated shock will feel unpredictable in a way no amount of setup changes will fix.