Dynamic Viscosity of SAE 30 Oil
| Value | 0.088 Pa·s |
| Status | Measured: ± 0.02 Pa·s (0.23 relative) |
| Source | SAE J300 / Engineering ToolBox |
| Categories | Material PropertiesEngineering & TradeFluid Properties |
| micropascal second | 88,000 μPa·s |
| millipoise | 880 mP |
| pound per foot hour | 212.87977 lb/(ft·h) |
| millipascal second | 88 mPa·s |
| centipoise | 88 cP |
| microreyn | 12.763321 μreyn |
| poise | 0.88 P |
| pascal second | 0.088 Pa·s |
| pound per foot second | 0.05913327 lb/(ft·s) |
| pound-force second per square foot | 0.0018379182 lbf·s/ft² |
| kilopascal second | 0.000088 kPa·s |
| reyn | 0.000012763321 reyn |
Learning zone
Lubricating oils are graded by kinematic viscosity, not dynamic: an SAE 30 monograde runs roughly 95–110 cSt at 40 °C and 9.3–12.5 cSt at 100 °C. Multiplying 100 cSt by a density near 876 kg/m³ gives about 0.088 Pa·s. The SAE numbers are grade bands, not measurements, and two SAE 30 oils from different refiners can legitimately differ by 15 %.
The temperature sensitivity is the whole story of lubrication. The same oil is around 0.4 Pa·s at 20 °C and 0.01 Pa·s at 100 °C — a factor of 40 — which is why cold starts are where engines wear and why multigrade oils exist. A 10W-30 is not "thicker when hot"; it is a base oil that behaves like a 10-weight at cold-crank temperature and like a 30-weight at operating temperature, achieved with viscosity-index improvers. Hydrodynamic film thickness in a journal bearing scales directly with viscosity, so an oil that has sheared down or been diluted with fuel loses its film long before it looks or smells wrong.