Finding out when to select synthetic gear oil.

Why would it be important to know when to select synthetic gear oil? Simply because the correct choice can save you time and money whilst reducing down time and repairs.

Although regular oil has been good enough for a hundred years or more.. I’ll explain why in this day and age it’s crucial to select synthetic gear oil.

Select synthetic gear oil to unleash several advantages.

When you select synthetic gear oil you gain the following application-related advantages resulting from the improved properties of synthetic lubricating oils when compared to mineral oils:

• improved efficiency due to reduced tooth-related friction losses 
• lower gearing losses due to reduced friction, requiring less energy 
• oil change intervals three to five times longer than mineral oils operating at the same temperature 
• reduced operating temperatures under full load, increasing component life; cooling systems may not be required

When you select synthetic gear oil gearing losses are minimised and efficiency improved.

Because of their special molecular structure, synthetic lubricants, based on poly-alphaolefins (a type of SHC) and polyglycols, ensure that tooth-related friction is considerably lower than with mineral oils. It may be up to 30 percent lower than if a regular mineral gear oil with EP additives was used. Because the friction coefficient of synthetic gear oil is lower, tooth-related friction is reduced, thus increasing the gear’s efficiency.

The efficiency of gears with a high sliding percentage, worm and hypoid gears, for instance, may increase up to 15 percent when you select synthetic gear oil instead of a mineral oil.


Even in the case of spur, helical and bevel gears (which have a naturally high gear efficiency), it is possible to increase gear efficiency of up to one percent by using a synthetic gear oil. This may not seem like much at first, but it may result in considerable cost savings depending on the nominal output of the gear unit, especially in the case where several gears are deployed.

Select synthetic gear oil to reduce friction and improve performance.

Increased Gear Efficiency

• Smaller gears with smaller motors can provide the same power output 
• Higher power output can be achieved with the same power input 

Reduced Oil Temperatures

• Extension of the oxidative life (five times longer than mineral oils in some cases) 
• Extended component life (where reduced wear and friction is achieved) 
• Cooling systems may no longer be required 

Reduced Energy Consumption

• Reduced costs for electric current or fuel consumption resulting from lower total energy losses in the gearbox; 30 percent and more for worm gears 
• Costs for electric power have been reported as high as 10 percent

 When you select synthetic gear oil you can improve efficiency and reduce wear.

A polyglycol oil offers the highest degree of efficiency: 18 percent more than the high performance mineral gear oil. SHC gear oil also made the test gears eight to nine percent more efficient. Its performance as a food-grade lubricant in accordance with USDA-H1 is also an excellent added advantage. Food-grade lubricants often mean that you have to select synthetic gear oil.

Synthetic base oils have excellent wear protection behavior, which is enhanced by appropriate antiwear additives. Wear is particularly low when the PAG gear oil is used.

When you select synthetic gear oil you can extended oil change intervals.

Synthetic oils have better resistance to aging and high temperatures and a longer service life than mineral oils. Depending on the base oil (SHC or PAG), the synthetic gear oil change intervals may be three to five times longer at the same operating temperature.

Approximate oil change intervals of gear oils at an operating temperature of 80°C are:

• Mineral oil: 5,000 operating hours • SHC oil: 15,000 operating hours (extension factor 3) 
• PAG oil: 25,000 operating hours (extension factor 5)

Because synthetic oils have a lower friction coefficient than mineral oils and a more favorable viscosity-temperature relationship it makes good sense to select synthetic gear oil with a lower viscosity grade which will reduce oil temperature during operation. In such cases, the life extension factors for oil change intervals of synthetic oil are longer than the values stated above, which refer to identical oil temperature. The following comparison of test results illustrates this advantage. Three lubricants were tested in a splash lubricated worm gear test rig.

The test records show the following oil sump temperatures after 300 operating hours:

• Mineral oil: 110°C 
• SHC: 90°C 
• PAG: 75°C 

When you select synthetic gear oil you can expect the following life extension factors as compared to mineral oil is as follows:

• Mineral oil = 1 
• SHC = 9.5 times longer 
• PAG = 31 times longer 

When compared to mineral oils, the oil change intervals may be five times longer if you select synthetic gear oil, under the same thermal conditions. Despite the fact that the purchase price of synthetics is higher than that of a mineral oil, the extended oil change intervals can offset these costs when taking into account the gear unit’s extended service life.

A comparison of the costs for mineral and synthetic offers a real opportunity to reduce maintenance cost and improve machine reliability when you select synthetic gear oil. There is also the advantage of reduced environmental impacts with lower lubricant disposal rates.

As crude based oils increase in cost, and the environmental impact becomes more important more businesses will select synthetic gear oil... to save money and the environment. Take a look at Habot Oil’s selection of quality synthetic gear oil, and give us a call if you would like to place an order or have a question.