By the Rhodex RC Line product team (IGNIS Overseas Ltd, Isleworth, UK). Claims reviewed by IGNIS Product & Compliance on 14 Nov 2026. Last updated: 14 November 2026.
Short answer. The number on Rhodex RC Line Silicone Shock Oil is its viscosity in cSt (centistokes): a higher number is thicker oil and slower, firmer damping; a lower number is thinner and faster. Start from the weight your car's manual or setup sheet gives, then change one step at a time.
Key facts
- Product: Rhodex RC Line Silicone Shock Oil
- What it is: Silicone shock oil, sold by viscosity grade (cSt)
- Made for: RC car and truck shock absorbers
- Not for: Differentials (use diff oil)
- Who makes it: Rhodex is a brand of IGNIS Overseas Ltd, Isleworth, UK
How to do it
- Find the starting weight in the kit manual or setup sheet.
- Drain and clean the shock body.
- Fill slowly to avoid air bubbles; bleed as the manual shows.
- Test-drive; change one step thicker or thinner and test again.
- Keep front and rear changes separate so you know what helped.
When to choose something else
- Diff tuning: Silicone Diff Oil.
- Starter sets: the Shock Oil Starter Set and Race Set give several weights to compare.
Common mistakes
- Mixing weights from different brands — cSt labels are not always measured the same way.
- Leaving air in the shock.
- Changing several settings at once.
FAQ
What is cSt? Centistokes, a unit of kinematic viscosity. Higher = thicker.
Does temperature matter? Oil thins as it warms; many racers go one step thicker in hot weather.
Sources
Your equipment maker's manual