The definition of fully synthetic oil
There are many so-called fully synthetic oils on the market, but they are not fully synthetic oils in the true scientific sense. Most of them are highly refined mineral oils (Group III), and fully synthetic oils in the true scientific sense can be divided into two types. The first type is poly-alpha-olefin (PAO), which is a macromolecular base liquid refined from ethylene and propylene extracted from crude oil through complex chemical reactions such as polymerization and catalysis. The other type is based on alcohols and fatty acids. host.
Before 2000, only lubricants based on PAO or esters would have the words "Full Synthetic" printed on the packaging. In 1999, the U.S. consumer rights organization Better Business Bureau ruled that Mobil's accusation that Castrol should not print the word "fully synthetic" on products made from third base oil was not valid because "fully synthetic" is a marketing term and not Science word on packaging. Since then, many lubricant manufacturers have called their products made with a third base oil fully synthetic.
Nowadays, some irresponsible small brands or irresponsible lubricant practitioners even claim that products made from lower-quality base oils are synthetic oils.
Common misunderstandings about oil
1) Identify the quality of engine oil from the packaging.
Many car owners try to identify the quality of an engine oil from the packaging when purchasing, but this is in vain. The packaging of a lubricating oil will only tell you the specifications and viscosity of the oil. You can only know the quality after using it. If you don’t want to do random testing, you can consult an experienced and impartial mechanic, or search the Internet for different people’s reviews of different brands of lubricants. Your comments will give you an objective answer.
2) The higher the viscosity of the oil, the better.
This is a very common misunderstanding. Generally, the higher the viscosity of oil, the thicker the oil film formed, poor fluidity, and high resistance, so it consumes more energy. Older cars generally use high-viscosity oil, and a thick oil film helps strengthen sealing. New cars or cars that have just been overhauled should use low-viscosity oil to save fuel. Of course, under severe driving conditions such as high temperatures in summer, idling, start-stop, etc., poor-quality low-viscosity engine oil is easily diluted and difficult to maintain normal oil film thickness, which is always detrimental to the life of the engine. Appropriate selection of oil with higher viscosity is beneficial in some cases, but it does not mean blind pursuit of high viscosity. If you are unsure about viscosity choice, refer to the user manual for recommendations.
3) Check the mileage when changing oil.
Many car owners are accustomed to changing oil based on mileage, which is unscientific. Oil change intervals depend on various factors. Driving style, road conditions (highway, urban traffic jams, climbing, air turbidity), outdoor temperature, fuel quality, and the quality of the oil itself will all affect the life of the oil. Mileage is just a reference. The best approach is to check the condition of your engine oil frequently, at least once a week. If the color has darkened, it feels a little rough, the viscosity is very different from new oil, there is a strong smell of gasoline or burning, or the oil change took too long, it should be changed. Of course, the simplest thing is, if you feel you need to change, you can.
4) As long as the certification is newer, the quality will be better.
Many lubricant practitioners who know little about oil products often refer to oils with newer certifications as oils with better quality, which leads to great misunderstandings about the concept of oil certification in workshops.
For example, your car’s owner’s manual requires the use of API SL specification engine oil. Will an API SM-certified semi-synthetic engine oil make your car perform better than an API SL-certified fully synthetic engine oil? The answer is: "no". There is no doubt that new specifications are generally higher than old specifications, but you must know that specifications are only the lower limit. The performance of many high-quality (of course more expensive) oil products often far exceeds the requirements for their own certification or even renewal certification, but many times , but due to market strategy or time considerations, the certification was not updated.
As for products with reasonable prices, even if they have relatively new certifications, they often just pass the test, and the quality will soon decline over time. Therefore, if you love your car, when choosing lubricant products, do not blindly pursue newer certifications, but choose products with better quality.
Is it correct to use the specified product?
Every time 4S oil is changed, the reception staff always warns car owners: "We do not need to specify original products, and we are not responsible for car failures." Therefore, many car owners can only accept the 4S store's offer helplessly or blindly. product. In fact, as long as you pay attention to the text in the car owner's manual, you can find that the car owner's manual only requires the specifications of the vehicle product and does not impose any restrictions on the brand. You know, in any case, if there are any similar regulations that conflict with antitrust and consumer rights laws and regulations, it will only be front-line personnel who say this to car owners. As long as they use products that truly meet the specifications required in the user manual, regardless of whether the vehicle is under warranty at a 4S store, the car manufacturer will be responsible for the quality of its products.
The characteristics of ester oil can be roughly divided into five categories,
Oil-like low-grade mineral oil
2. Oily mid-grade mineral oil
< p>3. Oily refined mineral oil (the peak performance score of mineral oil is less than 3 points, which is considered to be up to standard.)4. Fully synthetic oil PAO (such as Jinmeifu No. 1, Gray Shell, etc. The performance is close to 6 5. Fully synthetic oil and ester base, aviation grade. (Such as red line, MOTUL, etc. Performance of 8 points or above)
The types of base oils are divided into the following five categories:
First, traditional solvent-refined mineral oil;
The second is hydrocracking mineral oil;
The above two are called mineral oil. The base oil of mineral oil is the distillate of useful light substances (such as aviation oil, gasoline, diesel, etc.. ................................................................. ................................................................. .....................essentially exploiting the poor quality components of crude oil, which contain thousands of different Mixture molecules. Even if the refining technology is refined, undesirable substances and impurities cannot be completely removed.
Third, highly hydrocracked or hydroisomerized wax;
This basis. The oil raw materials are the same as the first two. The most deceptive one on the market now is that Castrol began to use grade III base oil VHVI (very high viscosity index) instead of the original formula PAO in 1999, and labeled it as "synthetic" - —Synthetic oil, many domestic brands are now imitating it. With the improvement of processing technology, there are now Chevron patents on VHVI: 1DW (Hydrocracking-Isomerization Dewaxing); MSDW (Hydrotreating-Isomerization Dewaxing) Hydroisomerization and Hydrocracking - Selective Dewaxing) ExxonMobil patent; Semi-synthetic oil basically uses MSDW technology, which is called synthetic technology.
The fourth category, polyalpha-olefin (PAO);
Polyalpha-olefin (PAO) is Exxon. Mobil's patented technology is to refine ethylene and propylene from gases or natural gases in crude oil into a basic liquid composed of macromolecules through complex chemical reactions such as polymerization and catalysis. The ingredients are artificially controlled through chemical reactions to achieve the expected molecular form. Its molecules are arranged in an orderly manner and are naturally resistant to external variables. Therefore, the synthetic oil has good physical properties and is naturally resistant to thermal stability, oxidation reactions, and viscosity changes. Much stronger than mineral oil.
The fifth category, other synthetic oils
are generally called lipids, including diesters, polyol esters, polyethers, silicone oils, phosphate esters, etc. Chemical synthesis refined from animal and plant (biological) fatty acids and alcohols. Esters are inherently oily. Other base oils (including PAO) require additives to achieve this property, and the polarity of esters can make oil film molecules. It is attached to the metal surface, so esters are the best in terms of lubrication performance.
So in summary, the lubrication performance is as follows: esters > PAO > XHVI, MSDW, VHVI and other three basic categories. Oil.
Although ester-based oil has good high and low temperature resistance and anti-wear properties, it is unstable in water, easy to corrode, has poor compatibility with oil seals and coatings, and has high production costs. Polyethers are slightly better than esters in water and oil, but are incompatible with mineral oils and additives, are also very expensive, and cannot be widely used.
As a base oil for vehicles, polyalpha-olefin (PAO) has good compatibility with additives, oil seal materials, coatings, mineral oils, etc., and is relatively cheap. In fact, many brands now use Mobil's PAO, but I'm embarrassed to explain.
Lipid synthetic oils such as MOTUL 300V are actually racing oils (the McLaren team sponsored by Mobil will not use Mobil’s No. 1 0w-40; Ferrari does the same), that’s because racing cars don’t care about economic performance (MOTUL 300V More than twice as expensive as Jinmeifu), the compatibility requirements are not high (engine, gearbox, etc.). often changed and corrected). The oil change interval of MOTUL300V (usually 1,500 kilometers) is also much shorter than that of Jinmeifu No. 1 (it can last for tens of thousands of kilometers with proper use). The reputation of lipid-based synthetic oils such as MOTUL300V also comes from the modified car market, which is different from the pursuit of ordinary car owners. This also explains why the three major brands have not introduced lipid-based synthetic oil to the automotive oil market. Therefore, MOTUL is not a top brand and is not suitable for ordinary car owners. It also explains why top car brands such as Mercedes-Benz, BMW, Ferrari, and Porsche do not choose MOTUL 300V (this sentence seems to imply that red line oil is the best and can be ignored).
Mobil 1 is a PAO synthetic oil.
PAO cannot be used alone as the base oil of lubricants for two reasons: 1. Pao has poor compatibility with rubber; 2.PAO is difficult to be compatible with additives. Therefore, Mobil 1 currently uses three types of synthesis, namely four types of PAOs, five types of esters, and five types of alkyl naphthalenes.
Esters are not only soluble in PAO, but also easily miscible with additives. In addition, esters have natural lubricating ability, and rubber parts can swell appropriately, thus overcoming the shortcomings of PAO. Alkyl naphthalene, as the future lubricant base oil, belongs to the fifth category of base oil, with low freezing point and high oxidation resistance. Therefore, in order to achieve high mileage, that is, a service life of 1.5W miles, Mobil 1 is also mixed with alkyl naphthalene. Moreover, all four types of base oils have natural cleaning capabilities, so cleanliness does not depend on additives.
Is the performance decline of engine oil due to the destruction of the molecular chain of the base oil?
I guess many car enthusiasts think so, but this is actually wrong.
Even if the old engine oil is replaced when it is due, whether it is mineral oil or synthetic oil, more than 95% of the molecular chains in the base oil have not been destroyed. The hydrocarbon molecules of the base oil in waste engine oil remain intact after processing procedures such as clay refining, and new additives can still be used within a certain range. In Europe, especially Germany, the ratio is 65%.
The attenuation of engine oil performance is most closely related to the loss of additives, dilution of fuel, carbon deposits, mixing of sludge, increase in water content, and changes in pH value. Many car enthusiasts always listen to the sound to judge the performance of engine oil. In fact, it often misleads your judgment. Most people feel that the engine sound is bad at 2000~3000KM. In fact, it is an illusion caused by excessive carbon accumulation in urban road conditions. At present, engine oil above SL level can be used stably for 10,000~15,000KM (is this number correct?). After running at high speed, the carbon deposits are removed, and the engine sound becomes normal again.
Synthetic oil base oil has better wear resistance than mineral oil?
Most people may think that synthetic oil is more wear-resistant than mineral oil because it uses PAO or ester-based oil. In fact, this is a wrong idea.
As far as a single base oil is concerned, before adding additives, whether it is mineral oil or synthetic oil, there is almost no anti-wear ability. The anti-wear properties of engine oil are provided by a complex of anti-wear additives, independent of the base oil. This is also a misunderstanding of many people. The anti-wear properties of modern engine oils are mainly provided by complex additives, while the base oil, whether mineral oil or synthetic oil, has almost no anti-wear properties. Although mineral oil contains trace amounts of active elements such as sulfur, nitrogen, and phosphorus, the content is too small to provide anti-wear capabilities. PAO or esters also need to add anti-wear agents to make up for their own shortcomings. Pao is similar to mineral oil. To achieve the same anti-wear effect, the amount of anti-wear agent required is equivalent to that of mineral oil, while engine oil mixed with esters requires more anti-wear agent.