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Semi-synthetic engine oil 5W40: specifications, reviews
Semi-synthetic engine oil 5W40: specifications, reviews

Today there are so many motor oils on the market that it is not at all easy to understand them and distinguish them from each other. This article will focus on one of the oil bases, a semi-synthetic type of oil. Viscosity is considered a very important indicator of lubrication. There is a classification that separates the oil according to this indicator. What is semi-synthetic 5W40? And how is it different from others? Let's talk about it in more detail.

Oil base

The base of motor oils is:

  • mineral;
  • semi-synthetic;
  • synthetic.

Mineral water is a natural product obtained from the distillation of fuel oil. The manufacturing technology of such a lubricant is simple. Therefore, their cost is low. They are effective and do not have a strong destructive effect on the motor elements. In all oils, including mineral oils, additives are added that have various functions. The main one is to reduce the friction of parts. However, due to high temperatures, they burn out quickly.

semi-synthetic 5w40
semi-synthetic 5w40

The problem has been solved in synthetic oils, which are obtained by molecular synthesis. They are characterized by much greater stability in comparison with the previous type under any conditions. Such oil is expensive, since the technology for its production is completely artificial.

Semi-synthetic grease

5W40, 10W40, 20W40 or any other viscosity index can be mineral, synthetic or semi-synthetic.

Semi-synthetics are obtained by mixing two bases: synthetics and mineral water. Moreover, the first component is added from thirty to fifty percent, and the second - from fifty to seventy percent. It represents a kind of middle ground, a compromise between natural mineral water and completely synthetic synthetics.

This base has better stability than mineral oil, but is inferior in quality to synthetic oil. However, under different conditions, it is the semi-synthetic look that is preferred over the synthetic version.

Semi-synthetic base benefits

For example, semi-synthetics will be better for the engine if the car has significant mileage. This view will be more useful for the engine, because synthetics give high carbon monoxide. In addition, a semi-synthetic base is chosen for highly accelerated diesel and gasoline units, as well as for turbocharged engines. It will show itself effectively even at a cold start.

This grease can be easily used at low temperatures. The only inconvenience that arises is that semi-synthetics (5W40) should change more often. But the prices for it are much lower than for synthetic oil.

lukoil 5w40 semi-synthetic
lukoil 5w40 semi-synthetic


This indicator means the ability of the lubricant to remain on the surface of engine parts and remain fluid at the same time.

Thus, dry friction of individual elements should not be allowed, and with increased work of the cylinders, it is necessary to ensure a minimum friction force.

Oil must be stable at different temperatures. Of course, one species simply cannot work equally well in extreme heat or severe cold. But the operating temperature of the engine oil is very different.

In this regard, a special classification of motor fluid according to the viscosity parameter was developed, which was called SAE. Thanks to her, it is easy to determine the temperature range where the operation of the motor will be absolutely safe for it. This indicator has both synthetics, and mineral water, and semi-synthetics.

oil 5w40 semi-synthetic characteristics
oil 5w40 semi-synthetic characteristics


Deciphering these numbers on the label of any motor oil is easy. The letter W means belonging to winter lubricants. But if at the same time another number is indicated through the dash, then this indicates the all-weather nature of the lubricant. For example, the 5W40 semi-synthetics we are considering is deciphered as follows.

5W means low temperature viscosity. Cold start will be possible at a temperature of thirty-five degreesbelow zero (that is, five must be subtracted from forty). This is the minimum temperature at which the engine can operate in a safe mode for itself. But this applies only to starting, since this characteristic no longer applies to a warm engine.

rosneft 5w40 semi-synthetics
rosneft 5w40 semi-synthetics

Based on this, we can conclude that if in the region where the vehicle is operated, the temperature does not fall below the twenty-degree mark, the car owner can purchase lubricant with any number in front of the letter W.

The number on the other side means high temperature. It is clear that the higher this indicator, the higher temperatures the engine is able to operate. It is necessary to strictly follow the viscosity index provided by the manufacturer of a particular machine. A motorist can ignore the recommended brand of oil, but the viscosity must be strictly observed.

shell semi-synthetic 5w40
shell semi-synthetic 5w40

Consider different 5W40 oil (semi-synthetic). The characteristics that manufacturers give are interesting. But also curious are the estimates of independent experts conducting experiments with different brands.

"Lukoil 5W40" (semi-synthetic)

On this basis, excellent characteristics are declared by the Lukoil Lux 5W40 oil manufacturer. This lubricant can be used for both gasoline and diesel units installed in cars, vans and light trucks.

The company claims that the brand "Lukoil 5W40" (semi-synthetic)provides intellectual protection to the motor, thanks to the new effective formula. Different operating modes activate different lubricant components.

For example, at low temperatures, “cold” components come into play, and at extreme high temperatures, on the contrary, “hot” ones, capable of maintaining optimal viscosity.

engine oil 5w40 semi-synthetic
engine oil 5w40 semi-synthetic

This brand has the following features:

  • provides maximum protection against corrosion and wear;
  • enables safe cold start at low temperatures;
  • reduces motor noise;
  • prevents the formation of deposits in the motor.

Assessed by independent experts

According to the results of the experiments and the feedback from drivers, this oil, along with recognized brands of foreign production, showed pretty good results. It has excellent energy saving performance, and other properties also proved to be at a high level.

The oil is of medium volatility and provides excellent protection in extreme conditions. However, due to the high content of sulfur impurities, it does not fully comply with European requirements.

But "Lukoil 5W40" (semi-synthetics), reviews from motorists are numerous, most of which are positive.

Semi-synthetics "Rosneft"

Rosneft Maximum oil stands out among the lubricants on this basis. This is semi-synthetic 5W40.

The company positions the product as having high properties againstcorrosion, as well as showing stability when running at stated temperature, excellent anti-oxidation and dispersant performance.

The oil is designed to work with turbocharged gasoline units and diesel passenger cars of both domestic and foreign production.

This Rosneft 5W40 (semi-synthetic) lubricant is excellent for use in Russian climatic conditions, as evidenced by numerous reviews from experienced motorists.

lukoil 5w40 semi-synthetics reviews
lukoil 5w40 semi-synthetics reviews

Oil will reliably protect the engine at temperatures from minus thirty to plus thirty-five. It also provides a "cold" start of the engine, wear resistance to the oxidation process, maintains the necessary pressure under different operating modes and prevents deposits inside the motor at high and low temperatures.

Assessed by independent experts

Lubrication tests also showed good results, and the cold start parameter of the oil gave impressive results. Feedback from motorists says the same.

Semi-synthetics "Shell"

Shell Helix HX7 5W40 can be distinguished from the oils of this category of the company. This oil is more effective than the mineral base of the same manufacturer. The active additives contained in it provide protection to the motor and such cleanliness at which the operation of the unit, according to the developers, is equated to a car that has just come off the assembly line.

It is possible to fill both petrol and diesel units with oilShell. Semi-synthetic 5W40 works out its resource almost twice as long as mineral-based. And its cost is several times lower than synthetic lubricants.

In addition, this 5W40 oil provides protective anti-corrosion properties to the engine and low viscosity at low temperatures. Semi-synthetics will perform especially well when refueling a used car that will not work in extreme conditions.

Evaluation of car owners

These indicators explain the good demand that this lubricant enjoys from the Russian consumer. In addition to low fuel consumption, drivers report easy starting at low temperatures.

These are interesting characteristics and ratings of motor oil 5W40, semi-synthetic. For a certain type of transport, it will be the best choice, surpassing even synthetic-based lubricants in its data.

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