Author: Reporter/Fan Jinghua2016-02-28 Views: 312
The engine is the heart of the car, there are many metal surfaces in the engine that rub against each other, these components move fast, the environment is poor, and the operating temperature can reach 400 ° C to 600 ° C. Under such harsh working conditions, only qualified oil can reduce the wear of engine parts and extend the service life. Therefore, engine oil is known as the “blood” of the car.
In December 2015, Consumer Report (WeChat: Consumer Report) commissioned a third-party authoritative testing agency to conduct a comparative test of 20 mainstream engine oils in the current market to help consumers purchase and use engine oil more rationally.
The test results showed that 5W-30 Mobil 1 was better and Castrol was weaker; 0W-40 BMW original engine oil is better, Nissan original oil is weaker.
The three major indicators are often not up to standard
Since the low-temperature dynamic viscosity and pour point reflect the low-temperature cold start performance, the foam characteristic is an indicator that affects the lubrication effect, while the foam characteristic at 93.5 °C reflects the state in which the vehicle is in most of the normal driving. The journal divides the weight of the test indicators according to this, which are: low temperature dynamic viscosity 25%, pour point 25%, foam characteristics 24 °C 5%, foam characteristics 93.5 °C 40%, foam characteristics 24 °C 5%.
The combined weighted average results showed that 5W-30 Mobil No. 1 and Nissan original engine oil were ranked in the top two and rated as excellent, while Great Wall Jinji and Castrol ranked lower and rated “fair”; 0W-40 BMW, Toyota Original Oil, and Mobil 1 ranked the top three with a rating of excellent, while Nissan Original Oil was rated “Fair”. (Figure 5, Figure 6)
For the comprehensive situation shown by the test results, Tan Zhiyi, deputy director of the petroleum inspection department of Guangdong Entry-Exit Inspection and Quarantine Technology Center, said that there are 21 indicators reflecting the comprehensive performance of engine oil, and three of them are selected here, which cannot fully reflect the comprehensive performance of engine oil. However, in the daily inspection of engine oil, the indicators that exceed the standard are mostly concentrated on these three, and many lubricant brands may be close to the critical value on these three indicators for cost considerations, and there will be excessive phenomena if you are not careful, while there are not many other indicators that exceed the standard.
ExxonMobil (China) Investment Co., Ltd. also said that the three indicators of low-temperature dynamic viscosity, pour point and foam characteristics are determined by the type of base oil and additives.
How to choose an oil
Combined with the situation encountered by daily consumers in the use of engine oil, Consumer Report (WeChat: consumerreport) gives the following suggestions:
First of all, determine the viscosity grade before use, which is the basis for selection. Engine oil is divided into 5W-30, 40, 50…, 0W-20, 30, 40…., etc. according to the viscosity grade, how to choose the grade according to the situation?
Here are some different views, there are from the weather division of the use area, it is more suitable to think that the north should use 5W, too far north can use 0W, the south can use 10W, and there are also from driving habits, think that often violent high-speed driving with W after 40 or more. There are also considerations from the degree of newness of the vehicle, it is believed that the general new car 20, 30 viscosity is enough, and when the engine is more than 10W kilometers, using 40, 50 is the right approach.
There are many opinions, and from different angles, there is some truth.
In this regard, ExxonMobil (China) Investment Co., Ltd. replied to this magazine that according to the vehicle’s maintenance manual, it can find out the relevant quality level and viscosity level that it meets, and the selection of oil only needs to meet / exceed this level.
Wu Jingyue, who has many years of experience in the automobile maintenance industry, pointed out that it is enough for ordinary users to use in accordance with the provisions in the “vehicle manual”, and the recommended level on the manual is determined by the automobile manufacturer according to the characteristics of the engine, and it is also the optimal solution after repeated testing. He also added that some special areas, such as special high temperature environments or low temperature environments, special modification designs need special consideration.
Secondly, is it better to choose mineral oil, semi-synthetic oil or fully synthetic oil?
Mobil engineers say fully synthetic oils have better low-temperature properties (such as low-temperature dynamic viscosity) and generally lower pour points than semi-synthetic oils. The reporter also noticed from the label on the oil product that in general, the quality grade of semi-synthetic engine oil will be higher than that of mineral oil. Therefore, it is recommended that consumers give priority to full synthesis and semi-synthesis under the premise of comprehensive consideration of cost factors.
Finally, on the purchase channel, fake engine oil is now flooding the market, so consumers need to buy in formal channels. The sales staff of Sinopec Great Wall Lubricants told reporters that their lubricants can only be guaranteed to be genuine at Sinopec gas stations and official websites, and those purchased through other channels cannot be guaranteed; Mobil and Castrol also said that only special dealers and regular 4S stores can guarantee the authenticity of the product, and others cannot be guaranteed. Therefore, it is necessary to remind consumers that there are still certain risks in buying in some small repair shops and small shops.
Remember to “shake” before using oil
In daily use, many consumers may change the oil is to release the old oil and fill the oil directly from the oil hole, but many people may not shake the engine oil vigorously before opening the bottle cap each time the oil is filled, and then pour it into the engine as soon as possible. Even in repair shops, maintenance masters will ignore this step.
In fact, the step of whether to shake the oil well before changing the oil is not optional. In the process of testing, this journal found that whether the sample was shaken relatively violently before the test had a direct impact on the test results. If it is not shaken vigorously, the foam characteristics will not meet the standard, but this point is not included in the test method specified by the national standard.
Tan Zhiyi told reporters that each lubricating oil manufacturer will add different additives to improve the performance of lubricating oil, these additives are different for each manufacturer, are trade secrets, some of the additives may have deposition or wall phenomenon after a long standing time, if not shaken, there may be test results that are not up to standard.
“For oil with such characteristics, I hope that manufacturers can add eye-catching tips to the instructions for use, otherwise some additives may not be added to the engine, which will affect the lubrication effect.” He pointed out.
Therefore, this magazine reminds consumers: in the future, before changing the oil, remember to shake it vigorously, otherwise the oil poured into it may not be the original “complete” qualified oil, which will affect the performance of the oil and even cause damage to the engine.