Castrol Optigear Synthetic RO 150
ISO VG 150 gear oil
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Key specs
| Spec | Value | Method |
|---|---|---|
| KV40 | 150 cSt | ASTM D445 |
| KV100 | 18 cSt | ASTM D445 |
| Viscosity index | 130 | ASTM D2270 |
| Pour point | -45 °C | ASTM D97 |
| Flash point | 210 °C | ASTM D92 |
| Density at 15 °C | 0.868 g/cm³ | typical |
Grade checks
- KV40 is inside ISO VG 150 (135–165 cSt).
- Computed viscosity index is 133 from the stored KV40 and KV100 (ASTM D2270). The listed index is 130, more than 2 points away.
Viscosity and temperature
ASTM D341 (Walther) fitted to the published KV40 and KV100. It is an interpolation between those two points, and it is not meaningful below the pour point. Move the control to read a temperature.
Classification
- Category: Gear
- Synthetic: Synthetic
- AGMA class: AS
- FZG fail stage: >=14
- Copper: 1
- Note: For gears used in rail traffic and mechanical engineering applications
Equivalents
| Oil | Score | Why |
|---|---|---|
| Mobil Mobil SHC 629 | 45 | same ISO 150, VI 166 vs 130, synthetic, pour -48 vs -45, flash within 15 °C, AGMA AS, buyable now |
| Shell Omala S4 GXV 150 | 35 | same ISO 150, VI 169 vs 130, synthetic, pour -45 vs -45, AGMA AS |
| Chevron Tegra Synthetic Gear 150 | 35 | same ISO 150, VI 162 vs 130, synthetic, pour -49 vs -45, AGMA AS |
| Mobil Mobil SHC Gear 150 | 30 | same ISO 150, VI 176 vs 130, synthetic, AGMA AS, buyable now |
| Chevron Meropa EliteSyn XM 150 | 26 | same ISO 150, VI 159 vs 130, synthetic, AGMA AS |
Scores use published typical data. This is not an exact equivalent, and it is not an OEM approval. Confirm the substitute with the machine builder.
Documents
- Product data sheet
- Safety data sheet
- Specs last read from the data sheet on 2026-09-09.
Related: Castrol, Optigear Synthetic RO, viscosity index calculator, ISO / SAE / AGMA chart.
Questions
Is Castrol Optigear Synthetic RO 150 an ISO VG 150 oil?
Yes. The catalogue lists it as ISO VG 150, which is a kinematic viscosity of 150 cSt at 40 °C, plus or minus 10 percent (135 to 165 cSt). Confirm the current data sheet before you fill a machine.
What is a Castrol Optigear Synthetic RO 150 equivalent?
No other brand in this catalogue clears the equivalents bar for this oil yet (same application, same grade, compatible base oil, and a score of 60 or more). That is not proof that nothing else works. Check the machine manual.
Can Castrol Optigear Synthetic RO 150 be mixed with another oil?
Mixing two oils that share a base family is sometimes done and sometimes a mistake. Do not mix this oil with a PAG. For any other mix, follow the maker's change-over guidance and the machine manual.
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