Group III base oils are highly refined Hydrocracked Oils. They are produced by iso-dewaxing process that provides very low sulfur and aromatic compound levels. Viscosity Index of Group III base oils is more than 120. Since they contain very few aromatics and thus have poor additive solubility. They are used as bases for engine oils and modern industry lubricants and bear conductivity that is virtually non-polar, having values less than10 pS/m. Group III base oils offer good performance in wide range of attributes as well as good molecular uniformity and stability. They are commonly mixed with additives and sold as synthetic or semi-synthetic products.
| Specification | SN150 | SN500 | GIII 4cST | GIII 6cST | Test Method ASTM |
| Kinematic Viscosity @ 100°C | 5 cSt | 11 cSt | 4.2-4.4 cSt | 5.8-6.2 cSt | D-445 |
| Viscosity index (VI) | 90 | 90 | 127 | 130 | D-2270 |
| Flash Point | 205°C | 235°C | 220°C | 220°C | D-92 |
| Pour Point | -6°C | -6°C | -18°C | -15°C | D-97 |
| Density @ 15°C | 0.870 kg/m³ | 0.885 kg/m³ | 0.836 kg/m³ | 0.841kg/m³ | D-1298 |
| Sulphur Content | 0.5 Wt.% | 0.4 Wt.% | 10 mg/Kg | 10 mg/Kg | D-2622 |
| Color | 2 | 2 | +26(ASTM D156) | +25(ASTM D156) | D-1500 |
| NOAK | 10 Wt.% | 6 Wt.% | 12 Wt.% | 7 Wt.% | D-5800 |
| Carbon Residue Content | 0.05 Wt.% | 0.1 Wt.% | 0.01 Wt.% | 0.01 Wt.% | D-189 |