Is it possible to use 5W40 oil instead of 5W30 in severe frost?
- December 5, 2023
- 0
Which engine oil to prefer for winter use is an eternal topic of thought for every generation of Russian car owners. But sometimes the simplest nuance at first
Which engine oil to prefer for winter use is an eternal topic of thought for every generation of Russian car owners. But sometimes the simplest nuance at first glance in the theme of “oil” puts a person before a difficult choice.
Even a technically illiterate motorist is sure that the properties of the motor oil in the car engine directly determine its well-being and service life under certain operating conditions. Winter, with its cold weather, is rightly considered a difficult period in the “career” of any internal combustion engine. And if particularly severe frost comes in the area where the car mainly lives, the engine will have to pass a severe test every time it starts.
Certain features of the lubricant located in the depths at such a time can help survive the temperature minimum or aggravate the situation. And then the car owner remembers that at the last maintenance he did not fill the engine with 5W30, as recommended by the car manufacturer, but with the “cooler” 5W40. The fact that the latter has a different viscosity may raise concerns about the effect of a “more different” lubricant on the drive unit at very low temperatures
In this regard, we should not forget that the indices “30” and “40” in the specifications of lubricants according to the SAE standard reflect the parameters of their kinematic viscosity at +100°C. For a “thirty” this should fall within the range of 9.2–12.7 mm²/s, and for a “forty” between 12.7 and 16.4 mm²/s. That is, a hypothetical 5W40 oil has one and a half times higher kinetic viscosity at high temperatures than 5W30 according to SAE.
Increased viscosity in the heated state is necessary to maintain the quality of lubrication of rubbing parts at a time when the power unit works in conditions close to overheating – as a rule, under very high loads. As for the winter-specific features, on the contrary, it is mainly associated with starting the “engine” at low temperatures.
The ‘frost’ characteristics are determined by the parameters describing the viscosity of the oil at low temperature – in this case ‘5W’. Index “5” shows that the oil retains a satisfactory degree of fluidity down to −35°C. According to SAE criteria, lubricants with the 0W index are even less sensitive to thickening in cold conditions. Their limit is as much as −40°C.
However, the relationship between the number before the Latin letter W in the lubricant’s viscosity index and the actual thickening temperature is not as simple as it seems. The temperature tolerances indicated on brand canisters clearly only work with regard to “mineral water” and “semi-synthetics”. At the same time, there are, for example, synthetic lubricants with an SAE index of 10W40, which remain completely liquid even at −50°C.
This confirms the fact that synthetic 5W30 or 5W40 can easily remain liquid even at −40°C. And they can be safely used in any frost typical of Central Russia.
photo AutoVzglyad
Even a technically illiterate motorist is sure that the properties of the motor oil in the car engine directly determine its well-being and service life under certain operating conditions. Winter, with its cold weather, is rightly considered a difficult period in the “career” of any internal combustion engine. And if particularly severe frost comes in the area where the car mainly lives, the engine will have to pass a severe test every time it starts.
Certain features of the lubricant located in the depths at such a time can help survive the temperature minimum or aggravate the situation. And then the car owner remembers that at the last maintenance he did not fill the engine with 5W30, as recommended by the car manufacturer, but with the “cooler” 5W40. The fact that the latter has a different viscosity may raise concerns about the effect of a “more different” lubricant on the drive unit at very low temperatures
In this regard, we should not forget that the indices “30” and “40” in the specifications of lubricants according to the SAE standard reflect the parameters of their kinematic viscosity at +100°C. For a “thirty” this should fall within the range of 9.2–12.7 mm²/s, and for a “forty” between 12.7 and 16.4 mm²/s. That is, a hypothetical 5W40 oil has one and a half times higher kinetic viscosity at high temperatures than 5W30 according to SAE.
Increased viscosity in the heated state is necessary to maintain the quality of lubrication of rubbing parts at a time when the power unit works in conditions close to overheating – as a rule, under very high loads. As for the winter-specific features, on the contrary, it is mainly associated with starting the “engine” at low temperatures.
The ‘frost’ characteristics are determined by the parameters describing the viscosity of the oil at low temperature – in this case ‘5W’. Index “5” shows that the oil retains a satisfactory degree of fluidity down to −35°C. According to SAE criteria, lubricants with the 0W index are even less sensitive to thickening in cold. Their limit is as much as −40°C.
However, the relationship between the number before the Latin letter W in the lubricant’s viscosity index and the actual thickening temperature is not as simple as it seems. The temperature tolerances indicated on brand canisters clearly only work with regard to “mineral water” and “semi-synthetics”. At the same time, there are, for example, synthetic lubricants with an SAE index of 10W40, which remain completely liquid even at −50°C.
This confirms the fact that synthetic 5W30 or 5W40 can easily remain liquid even at −40°C. And they can be safely used in any frost typical of Central Russia.
Source: Avto Vzglyad
Donald Salinas is an experienced automobile journalist and writer for Div Bracket. He brings his readers the latest news and developments from the world of automobiles, offering a unique and knowledgeable perspective on the latest trends and innovations in the automotive industry.
