Why is there so much hype about selecting synthetic gear oil? 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 use synthetic gear lubricants.

Application-Associated Benefits when selecting synthetic gear oil

The following application-associated
benefits result through the improved qualities of synthetic oils when compared to petroleum based oils:

• enhanced performance because of decreased tooth-related friction losses
• reduced gearing losses due to reduced friction, demanding much less energy
• oil change time frames three to five times longer than mineral oils working at the exact same temperature
• decreased operating temperatures under full load, improving component life; cooling systems might not be required

By selecting synthetic gear oil gearing losses are minimised and efficiency improved

Simply because of their unique molecular composition, synthetic lubricating oils formulated on poly-alphaolefins (a type of SHC) and polyglycols make sure that tooth-related friction is substantially lower than with petroleum based oils. It may be up to 30 percent lower than if a regular petroleum based gear oil with EP additives was being used. Because the friction coefficient of synthetic oils is lower, tooth-related friction is decreased, thus improving the gear’s efficiency.

The performance of gears with a high sliding percentage, worm and hypoid gears, for instance, may improve up to 15 percent by selecting synthetic gear oil rather than a mineral oil. Even in the case of spur, helical and bevel gears (which have a naturally high gear performance), it is feasible to improve gear efficiency of up to one percent by making use of a synthetic gear oil. This might not appear to be very much at first, but it might result in substantial cost benefits based on the nominal output of the gear unit, particularly in the case where a number of gears are used.



Table 1 shows some excellent reasons for selecting synthetic gear oil.

Benefits of selecting synthetic gear oil Based on Reduced Friction
Improved Gear Efficiency

• More compact gears with more compact motors can supply the same power output
• Higher power output can be achieved with the same power input
• Decreased Oil Temperatures
• Improvement in the oxidative life (five times longer than mineral oils in certain cases)
• Prolonged component life (where decreased wear and friction is achieved)
• Cooling systems may no longer be required
• Reduced power usage
• Decreased expenses for electric current or fuel consumption resulting from reduced total energy losses in the gearbox; 30 percent and more for worm gears

Selecting synthetic gear oil leads to Increased Efficiency and Decreased Wear

Reports show selecting synthetic gear oil make gears more effective than mineral oils. A polyglycol oil in the study resulted in the greatest increase in performance: 18 percent more than the high performance petroleum based gear oil. SHC gear oil also made the test gears eight to nine percent more efficient.

Its overall performance as a food-grade lubricant in compliance with USDA-H1 is also an exceptional added benefit. Food-grade lubricants are often regarded as inferior to normal lubricants, an outlook which this research appears to disprove.

Synthetic base oils have excellent wear protection performance, which is improved by suitable antiwear additives. Wear is especially low when the PAG gear oil is being used.

Extended Oil Change Intervals when selecting synthetic gear oil

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

Estimated oil change intervals of gear oils at an working temperature of 176°F (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)

Synthetic oils have a lower friction coefficient than mineral oils in a gearbox and a more positive viscosity-temperature relationship. Thus selecting synthetic gear oil at lower viscosity grades also presents the potential of reduced oil temperature during operation. In such instances, the life extension factors for oil change intervals of synthetic oils are longer than the values mentioned above, which relate to the same oil temperature.

The following comparison of test results demonstrates this advantage. Three lubricants were tested in a splash lubricated worm gear test rig.

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

• Mineral oil: 230°F (110°C)
• SHC: 194°F (90°C)
• PAG: 167°F (75°C)

The life extension factors when selecting synthetic gear oil as compared to petroleum based oil is as follows:

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

Selecting synthetic gear oil Helps reduce Maintenance and Disposal Costs

As compared to mineral oils, the oil change intervals may be five times longer, when selecting synthetic gear oil, under the same thermal conditions. Regardless of the fact that the cost and the costs of disposal of synthetics are higher than that of a mineral oil, the prolonged oil change intervals can counteract these costs when considering the gear unit’s prolonged service life.

A comparison of the costs for mineral and synthetic offers real opportunity to reduce maintenance cost and improve machine reliability. There is also the benefit of reduced environmental impacts with lower lubricant disposal rates.

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