Spreading an extraordinary amount for the 75W90 gear oil , usually motorists are sure that this is an acceptable quality lubricant. You can try to go even further and choose a liquid that would suit a particular car model, and for the money was not super expensive.
Transmission Classes
Lubricants of the Gl group are hypoid. That is, they lubricate the rear axles and individual gearboxes of such domestic car brands as Zhiguli, Niva, Volga. For trucks, of course, it is also suitable, but it will cost too much.
The most common is transmission oil 75W90 viscosity grade. Exceptions included Castrol brand oils. Their range includes 85W90 and 80W90 more fluid lubricants. In addition, transmission oil 75W140 stood next to GL 5 75W90. This last viscosity option is not very suitable for Russian cars. It is usually poured onto the rear and all-wheel drive versions, as well as in models with a locked differential. Most likely, they will serve perfectly on the Patrol or Land Cruiser, and for the Russians they will be too thick. Pouring them during normal operation does not make sense. But if the rear axles are "sung", then such a lubricant can be just right for them.
But if an inexpensive mineral water copes with its functions perfectly, why spend extra money on synthetics?
Different viscosity gear oils
Among engine oils, a fully artificial synthetic base has long gained the greatest popularity. The transmission oil 75W90, 85W90, 75W140 also extends behind them. Most synthetic-based lubricants can be used all year. Even at very low temperatures, they will give good functional results. For example, if you compare mineral water 85W90 at negative twelve degrees with synthetics 75W140 in frost at forty degrees, then the result in viscosity will be practically indistinguishable. And if they are placed in one temperature mode at -20 degrees, then the result will be different 30-50 times. This is a very serious backlog. It turns out that in one case the engine will start barely, and in the other - almost like in the warm season.
Lubricant Testing
Advantages will be revealed even more if you try them in operation under extreme conditions. Under heavy loads, lubricating fluids become more fluid. Therefore, appropriate tests were carried out. Of course, it was expected that those that are of higher quality will behave better here and show the most consistent results. And so it happened.
A clearer result will be visible in numbers. The welding load on a conventional 4-ball friction machine reveals the ability to hold a critical load. According to it, the oils are divided into groups. So, GL 3 has a minimum value of 2760, transmission oil 75W90 - GL 4 - 3000, and GL 5 - 3280.
Test results
And the test results were as follows. The cheapest 85W90 viscosity oils ranged from 2607 to 4635H. The average indicator for them is 3827N. It would seem that it exceeds even GL 5. But let's look further. AvtoVAZ needs a transmission with an indicator above 3483N, and AZLK - 3924N. To meet such requirements, the result no longer seems to be excellent.
Another test oil had a viscosity of 80W90. Its average value gave the number 4122N, which is already much better. An even better result was shown by 75W90 gear oil. Here, the values ranged from 3685 to 5204N, and the average indicator gave 4508N, which, of course, was good.
The best results, of course, were given with a viscosity of 75W140. However, such a transmission is hardly necessary for everyone.
So which oil to pour?
Summarizing the foregoing, we can conclude that if the operation of the vehicle is expected at a temperature not lower than -12 degrees, then it is quite possible to do with oil with a viscosity class of 85W90. This is the most inexpensive option, and domestic production will cost quite cheaply.
If the temperature in the area drops to 26 degrees below zero, then you need to purchase 80W90 oil. With him, at this mark, the car will feel more confident.
Well, the transmission oil 75W90, reviews about which can be found on the network very often, and especially the viscosity grade 75W140, already remains for lovers of extreme driving. Of course, and the price will be higher.
Having calculated the required amount (for example, on the Zhiguli - the rear axle takes about three liters) and compared with the mileage (on the same brand, replacement is required every 60,000 km), each motorist can calculate how much money this or that oil will cost him , and based on these data to make a choice.
If we talk about specific brands of transmission lubricating fluids, we can note several foreign oils that showed good results:
- Wellrun showed a record for load welding.
- Liqui Moli - the absolute record for resistance to cold.
- Castrol 75W140 is the best result in overheating resistance.
- Spectrol Synax (domestic brand) met all the standards, but did not reach the high requirements.