The following engine oil classifications are set by the API (American Petroleum Institute) .
【API Service for Gasoline Engine Oils】
Item | SH | SJ | SL | SM | SN |
---|---|---|---|---|---|
Oxidation stability | ☆ | ☆ | ☆☆ | ☆☆☆☆ | ☆☆☆☆ |
Anti-sludge performance | ☆ | ☆ | ☆☆ | ☆☆ | ☆☆☆☆ |
Wear resistance of variable valve train system | ☆ | ☆ | ☆☆ | ☆☆☆ | ☆☆☆☆ |
Rust prevention performance | ☆☆ | ☆☆ | ☆☆ | ☆☆ | ☆☆ |
Low volatility performance | ☆ | ☆☆ | ☆☆☆☆ | ☆☆☆☆ | ☆☆☆☆ |
Shear stability | ☆ | ☆ | ☆ | ☆ | ☆ |
Deposit control at high temperature | ☆ | ☆☆ | ☆☆☆ | ☆☆☆☆ | ☆☆☆☆ |
Compatibility with oil seal | ☆ | ☆ | ☆ | ☆ | ☆☆ |
Compatibility with exhaust catalyst | ☆☆ | ☆☆☆ | ☆☆☆ | ☆☆☆☆ | ☆☆☆☆ |
Anti-foaming performance | ☆☆ | ☆☆☆ | ☆☆☆☆ | ☆☆☆☆ | ☆☆☆☆ |
Cold startability | ☆ | ☆☆ | ☆☆ | ☆☆ | ☆☆ |
Filterability | ☆☆ | ☆☆ | ☆☆ | ☆☆ | ☆☆ |
☆marks in total | 16 | 21 | 28 | 33 | 37 |
【API Service for Diesel Engine Oils】
Item | CC | CD | CE | CF | CF-4 |
---|---|---|---|---|---|
Piston cleaning efficiency | ☆ | ☆ | ☆☆ | ☆☆☆ | ☆☆☆ |
Soot dispersion capability | ☆ | ☆ | ☆ | ☆☆☆ | |
Wear resistance | ☆ | ☆ | ☆ | ☆☆ | |
Rust prevention performance | ☆ | ☆ | ☆ | ☆ | ☆ |
Low volatility performance | ☆ | ☆ | ☆ | ☆ | ☆☆ |
Shear stability | ☆ | ☆ | ☆ | ☆ | ☆ |
Compatibility with oil seal | ☆ | ☆ | ☆ | ☆ | ☆ |
Anti-foaming performance | ☆ | ☆ | ☆ | ☆ | ☆ |
☆marks in total | 6 | 8 | 9 | 10 | 14 |
【API Service for Gear Oils】
GL-1 | Spiral bevel gear, worm gear and manual transmission with low face pressure and low sliding velocity. |
---|---|
GL-2 | Worm gear, not applicable to GL-1 because of requirements such as load, temperature and sliding velocity. |
GL-3 | Manual transmission and spiral bevel gear having mid-range sliding velocity and loading conditions. |
GL-4 | Gears of vehicles, especially Hypoid gear, operated under high speed & low torque or low speed & high torque conditions. |
GL-5 | Gears of vehicles, especially Hypoid gear, operated under high speed & impact load, high speed & low torque or low speed & high torque conditions. |
↑Higher numbers followed after GL do not necessarily mean high quality products.