Gear oils are specifically designed lubricants used for the lubrication and protection of gears in various industrial and automotive applications. They come in different types, each formulated with specific properties to suit different gear systems and operating conditions.
DIGNOLUB Gear oil is available with various ISO VG grades and SAE grades. Multi-grade oils meeting API GL4 and GL5 requirements are available for the user to select according to his or her needs.
Various grades of DIGNOLUB Gear Oil are summarized in the following chart:
| ISO Viscosity Grade | SAE/API Grades |
| ISO VG 68 | SAE 80 API GL4 |
| ISO VG 100 | SAE 90 API GL4 |
| ISO VG 150 | SAE 140 API GL4 |
| ISO VG 220 | SAE 80W/90 API GL4 |
| ISO VG 320 | SAE 85/140 API GL4 |
| ISO VG 460 | SAE 80 API GL5 |
| ISO VG 680 | SAE 90 API GL5 |
| SAE 140 API GL5 | |
| SAE 80W/95/140 API GL5 | |
| SAE 80 API GL5 |
ISO-grade gear oils :
The single number denotes the mid-point viscosity in centistokes. A higher VG number indicates higher viscosity of the gear oil.
SAE/API Grades :
Monograde (SAE 80, 90, 140) and Multigrade (SAE 80W/90, SAE 85W/140) gear oils meeting API GL4 and GL5 requirements come under this category.
The SAE grading system has the advantage over the ISO system in that it defines the viscosity performance of the oil at both the low-temperature range and the high-temperature range.
What do GL4 & GL5 signify in Gear Oils :
GL4 gear oil is a lower-viscosity oil designed for use in older cars with manual transmissions. Generally, it should be used under moderate speed and load conditions. This type of gear oil is compatible with bearings or synchronizers made with yellow metals. You can also use it in newer cars with manual transmissions, but it may not provide as much protection as GL5 gear oil.
GL5 gear oil is a higher-viscosity oil that is suitable for use in newer cars with automatic transmissions. It can be used in manual transmission also. It is typically recommended for use under high speed and load conditions.
The difference between GL-4 & GL-5 lies in the amount of extreme-pressure (EP) additives they contain. EP additive is designed to protect gear surfaces from wear and tear, and the higher the concentration of these additives, the more effective the protection will be.
As a result, GL-5 gear oil is typically used in high-pressure applications such as differentials at the front and rear axles. Although it costs more than GL-4 gear oil, the added protection it provides can save you money in the long run by extending the life of your gear.
