In 2019, an independent examination of motor oils presented on the domestic market was conducted in Ukraine. To check the quality, the Institute of Consumer Expertise took 10 brands of 5W-40 oil from different manufacturers.
The previous test was related to the cancellation of the state certification system UkrSEPRO. In fact, this means that it has become not mandatory, but voluntary. Autoportal.ua decided to study this topic in more detail and analyze the dependence of the price of motor oil, brand reputation, and its quality. A separate point is the change in price over the past years.
Of the 10 samples, exactly half (Castrol, Liqui Moly, Nanoprotec, Aral, and ZIC) are classified as ACEA C3. Roughly speaking, such oils contain less sulfur, phosphorus, and sulfated ash than oils of the A3/B4 category (the letters "A" and "B" determine the engine type – for gasoline or diesel, and these are oils: Elf, Shell, Kroon-Oil, Mobil, Xado). Oils with ACEA C3 approval are intended for vehicles of environmental class not lower than Euro 4 and are compatible with catalysts and particulate filters.
IMPORTANT: it is not allowed to use oils of an earlier generation for new cars than provided by the manufacturer. The same applies to using new generation oils in old cars. Before purchasing, it is necessary to look at the operating manual and/or consult with specialists so that the requirements and approvals correspond to the specific car.
Testing methodology
Motor oil quality studies were conducted at the testing center of the research institute "MASMA" in Kyiv, which is considered one of the most authoritative institutions in this field. Each sample was checked for basic physical and chemical properties, after which laboratory and bench testing methods were carried out. The latter allow simulating the use of oils in real conditions, including the most extreme ones.
The video will tell in more detail:
Physical and chemical tests
According to the main physical and chemical properties, all 10 oils successfully passed the laboratory check. All samples meet the declared characteristics and comply with the standards.
Standards according to the European ACEA classification:
For category A3/B4:
Total base number not less than 10.0 mg KOH/g, sulfated ash content from 1.0 to 1.6%.
For category C3:
Total base number not less than 6.0 mg KOH/g, sulfated ash content not more than 0.8%.
Bench tests
As bench tests showed, oils from 3 manufacturers "failed" the corrosion test on lead plates. And this is actually a very important point, because it determines how well the oil can protect engine parts from corrosion. Excessive corrosive activity was shown by:
- Castrol
- Kroon-oil
- Xado
Corrosiveness of oils
* - absence of corrosiveness up to 5 g/m2.
Induction period of sediment formation
What is this? If you do not go into details, then if the mass content of sediment is less than 0.5%, then the specific sample passed the test and has good antioxidant properties. In addition, good antioxidant properties are characterized by minor changes in relative viscosity and acid number.
According to these parameters, the best were:
- Nanoprotec
- Shell
- Kroon-Oil
But the outsider was Xado oil – it has the worst indicators.
Tribological characteristics on a four-ball machine at 20±5°C
These tests were carried out on a four-ball friction machine to determine the critical load, wear index, and seizure index, ultimately to evaluate the lubricating properties of oils. In this case, samples need to be evaluated collectively according to three parameters with the separation of oils by class.
ACEA C3 class
- Liqui Moly
- Nanoprotec
- Aral
- Castrol
- ZIC
A3/B4 class
- Elf
- Shell
- Kroon-Oil
- Mobil
- Xado
Test results
Which oil should you pour? Based on the results of the quality check of 5W-40 motor oil, it is not easy to unambiguously determine the leaders – there are better and worse ones. After all, in this case, it is necessary to take into account the totality of the results shown in relation to the price. And this is the most interesting thing – as the test trials showed, a high price is not a guarantee of high quality.
How oil prices have changed
Not only housewives but also motorists know about the unprecedented rise in sunflower oil prices in 2021. As for automotive motor oil, it cannot be said that it has skyrocketed in price, but the cost has still changed, and for some brands significantly.
So, for example, for Liqui Moly, Castrol, and Mobil, it has risen by more than a third. And if Liqui Moly got into the top three leaders, then Castrol can hardly be called one of the best, despite brand recognition and the very (!) high price (as of 2021) among the oils that participated in the examination.
Shell, Elf, and Nanoprotec showed an average increase in cost. Kroon-Oil and Xado, which showed some of the worst test results, rose the least. And if Kroon-Oil was and remains one of the cheapest oils on the market, then Xado cannot be called that.
It should be noted that Nanoprotec and Liqui Moly can be considered the favorites of the quality test in the ACEA C3 class – they are closest in characteristics. True, taking into account the rise in price, in terms of price/quality ratio, Liqui Moly loses to Nanoprotec – in 2019, the former was almost 20% more expensive than the competitor, while this year the price difference between Liqui Moly and Nanoprotec has increased to 37%.
As for the A3/B4 class, the research leaders Elf and Shell have risen in price by 20% and therefore are comparable both in price and quality (as of both 2019 and 2021).
