When choosing engine oil for their own car, drivers are primarily guided by the tolerances specified in the technical documentation of the engine. With the development of the fuels and lubricants industry and changes in the market for these products, oil change issues sometimes arise.
Lubricating fluids 5w20 and 5w30 differ not only by viscosity but also in price. Some service centers and specialists advise using these products interchangeably. This is due to some of the features of logistics. What do each of these lubricants represent?
General requirements for lubricants
Any mechanism that makes movement needs lubrication. This is necessary to protect parts from dry friction, which results in wear and the appearance of defects on metal surfaces. Correctly selected lubricant increases the service life. The use of an incorrectly selected oil can lead to the failure of engine parts and the need for an overhaul.
The main tasks of engine oil:
- reduced wear of engine parts;
- resistance to corrosion, aging and other negative factors;
- neutralization of carbon deposits and removal of sludge;
- maintaining thermal stability.
In addition, the product needs to be highly volatile and not foam too much. Any oil must retain its characteristic properties in the specified temperature regime, which is indicated by a special marking.
The decoding of the 5w20 value indicates that the oil is designed to work in the following range: cold engine start is carried out at a temperature of minus 30 degrees Celsius, and the positive temperature limit is indicated by + 20C. This means that the viscosity of the product is sufficiently low, which reduces friction in the components of the power unit. Under these conditions, the motor can operate at its maximum power. The only drawback is the rupture of the oil film on the surfaces of the parts due to prolonged downtime in traffic jams.
The last digit of the SAE marking also denotes the thickness of the film that forms on the working surfaces to protect parts from the effects of dry friction.
The w mark indicates that the product is suitable for winter use. Thus, 5w20 engine oil belongs to all-season lubricants.
Modifications of lubricants marked 5w20 are available for gasoline and diesel units, suitable for both old models and new products in the automotive industry.
Benefits of 5w20:
- high-level motor protection;
- efficiency when working with any kind of units (diesel and gasoline);
- maintaining its qualities at idle;
- due to the unique composition, the product does not undergo evaporation.
When using 5w20 engine oil, fuel savings are observed.
Comparative characteristics of oils
5w30 is a multigrade oil for gasoline engines. This product is distinguished by its viscosity index and the value of the positive temperature limit. The temperature range at which 5w30 does not lose its qualities: from -30C to + 30C. This grease can be used in any season for most Russian regions. This product also has a higher protective film thickness than 5w20. An important aspect is the relatively low price of the product, in contrast to the previous one.
Many car enthusiasts have the question of what to choose, 5w20 or 5w30, what is the difference, and which is more preferable to use. Both lubricants have low viscosity and good fluidity. These qualities help to better remove excess heat.
Both products are classified as free-flowing lubricants. Which one to choose will be prompted by the technical documentation of the vehicle engine. They are often referred to as interchangeable oils. At the same time, it is wrong to approach the choice from the position of which oil is better. The temperature should be a key factor. Even minor changes in the qualitative composition can significantly change the operational properties.
Thus, both products have similar characteristics. When used, their motor will operate with high efficiency due to the flow characteristics. And only one factor limits the application: a relatively low positive temperature limit. These types of lubricants are not suitable for operation in regions with hot summers.
5W-20 or 5W-30 – which is better
In this matter, there is no such thing – better or worse, depends on many factors: the brand of the oil, the existing tolerances, etc. You also need to choose based on the recommendations of the engine manufacturer, if the use of 5W-20 is allowed, and it is suitable for the climate of the region where the car is operated, then you can fill it in for the sake of saving fuel. But it is worth remembering that this oil is not for hot climates.
If the car “eats up” the oil, then it is better to use 5W-30, again, if there is a recommendation for such a viscosity from the engine manufacturer, but at the same time understand that increasing the viscosity of the oil used will solve the problem only for a while, you need to check the engine and find the reason for the increased consumption.
With regard to use in winter, both of these oils are “winter”, that is, they can be used in any season, but are suitable for low and very low temperatures. When choosing, you need to be guided not only by the specified SAE, but also by the technical characteristics. For example, the oils mentioned just above have the following pour point: SHELL Helix Ultra 5W-20 -36 degrees, 5W-30 -52, although there should not be a difference between them, but it is significant.
Also, when choosing, we pay attention to the dynamic viscosity of the CCS cold-cranking simulation – the lower the indicator, the easier it is for the starter to crank the cold engine. If the characteristic is at the uppermost limit, which for 5W is 6500, there will be no margin, starting the engine at -30 will be quite risky, and further upward – the lower the indicator from the redistribution, the greater this margin will be, the engine will start quickly and safely.
Can 5W-20 and 5W-30 be mixed
In theory, yes, but it should be borne in mind that the viscosity will become average between these values, that is, 5W-25, depending on the proportions. If you have already decided on mixing, it is better to use the products of one manufacturer, and not to abuse such things at all, but to use the same oil both for topping up and replacing.