Gasoline engine oil

Gasoline octane rating: The # symbol indicates the octane value of gasoline. 90, 93, 97, 98. 　　The so-called 97-octane gasoline consists of 97% isooctane and 3% n-heptane. For engines with a high compression ratio, high-octane gasoline should be used; if low-octane gasoline is used in such engines, it can lead to abnormal combustion, resulting in knocking, increased fuel consumption, and reduced driving performance. Engine oil, also known as engine lubricant, is regarded as the “blood” of a car; it serves to lubricate, clean, cool, seal, and reduce friction in the engine, which is a well-known fact. So, for the 2003 automotive engine oil market, which products will the major manufacturers focus on promoting? What are the differences between the various products? The owner may not be able to answer these two questions clearly. 　　Standards related to automotive lubricants Viscosity standards: The SAE (Society of Automotive Engineers) viscosity classification is used to determine the different temperature ranges for which a lubricant is suitable. 　　Performance standards: The API (American Petroleum Institute) performance classification is primarily used to distinguish the performance and quality of lubricants. 　　Other classifications include ACEA (Association of European Automobile Manufacturers), JASO (Japanese Automotive Standards Organization), and the classifications of various engine manufacturers.

For engine oil to perform its primary function—lubrication—its viscosity (which measures its consistency or resistance to flow) must remain stable even when the engine is under extreme temperatures. Oil becomes thinner when heated and thicker when cooled. Therefore, it is very important to choose the appropriate oil type based on the temperature in the geographical area where you live. The single-stage type is designed for oils whose viscosity is determined at only one temperature, regardless of the temperature level. Multi-stage systems must simultaneously meet different viscosity requirements at high and low temperatures. A dual-stage system is a simple and convenient option for drivers who have to endure extreme cold and heat. The dual viscosity of oils is easy to identify (for example, 10W-30: 10W indicates low temperatures, meaning it is suitable for use in winter, while 30 indicates high temperatures). It is the viscosity-modifying additives that cause the oil to thicken at high temperatures, while having no effect at low temperatures. Information on the performance, viscosity grades, and storage characteristics of oils can be found in the API Service Manual, which is also known as “Donut”. This symbol represents the API (American Petroleum Institute) rating, a grade defined by two letters that indicate the quality level of the engine oil and the vehicles for which it is suitable. The first letter “S” stands for its suitability for “spark ignition,” that is, gasoline engines. The first letter “C” stands for “compression ignition,” meaning it is suitable for diesel engines. The second letter represents the performance in different categories. In the categories starting with "S", the performance levels increase in alphabetical order. However, the ordering within the categories starting with “C” is not exactly the same, mainly because there is a great variation in the types and applications of diesel engines. Therefore, following the recommendations in the user manual is quite important. The focus of the manual is the SAE (Society of Automotive Engineers) viscosity classification. At the back of the manual are details on the storage properties of oils determined through standardized testing. If the oil meets the latest standards for category “S” as well as the current storage standards, it can use the API certification mark known as “Starburst”. The Starburst logo is always displayed on the front of the label. Engine oil – basic knowledge: We are in agreement that it is very important to change the oil at regular intervals. Clean oil plays a crucial role in the smooth operation of vehicle engines. But you may still not be very clear about what engine oil actually is and how it works. Let’s start with the basics first. The fuel used in vehicles consists of two basic components: base oil and additives. The base oil enables the engine oil to perform its basic function of lubricating the moving parts of the engine, thereby preventing damage to the engine due to friction. Additives, on the other hand, provide additional protection for the engine by preventing the engine oil from failing under extreme temperature conditions. Base oil is refined from crude oil (crude oil refers to petroleum in its natural state extracted from underground). Crude oil must undergo several refining processes before it can be used to produce engine oil. Unwanted components such as white oil, sulfur, and nitrides must be removed. Unsaturated hydrocarbons must be extracted or converted into more stable molecules. Crude oil is first separated into a series of fractions or viscous molecules through vacuum distillation. These fractions used in the production of base oils are further processed through various combined refining processes, such as solvent extraction – a natural method for separating saturated and unsaturated hydrocarbons. Hydrorefining – Removes nitrides and sulfides, enhancing color, oxidizing properties, and heat resistance. Hydrogenation – Converts unsaturated hydrocarbons into saturated hydrocarbons before solvent extraction to speed up separation. This method can also help remove a large portion of sulfur and some nitrides. Hydrocracking – this is a complex process in which the molecules in crude oil are rearranged to form the desired saturated hydrocarbon molecules. This method produces far more saturated molecules than hydrogenation and solvent extraction. Hydroisomerization – used in conjunction with hydrocracking, it converts the molecules in crude oil into their most stable form. Using only base oil cannot fully protect the engine. Engine oil must perform its various functions under different engine operating conditions. Therefore, various additives must be included in the formula: Cleaning/detaching additives – used to keep the engine clean by suspending different types of dirt and preventing them from settling and clogging the engine’s components. Anti-corrosion and rust-preventing additives – protect the engine from damage caused by combustion byproducts such as water and acidic substances. Antioxidants – inhibit the oxidation processes that lead to oil thickening and sludge formation. Anti-wear additives – create a film on metal surfaces to prevent friction between metals. Viscosity modifiers and pour point depressants – help improve the fluidity of the oil. Now that you understand what engine oil is, how it is produced, and its functions, here comes a concept that is often confusing: the grade. To enable engine oil to perform its primary function—lubrication—its viscosity (a measure of concentration or flowability) must ensure that it can function properly even when the engine is under extreme temperature conditions. Oil becomes thinner when heated and thicker when cooled. It is particularly important to choose the appropriate viscosity based on the geographical and climatic conditions. Physical and chemical properties: Diesel is primarily composed of alkanes, olefins, cycloalkanes, aromatic hydrocarbons, and polycyclic aromatic hydrocarbons, along with small amounts of sulfur (2–60 g/kg) and nitrogen (5 ml/kg). Toxicity can vary depending on the impurities and additives (such as thioesters, etc.). It is irritating to the skin and mucous membranes. It can also have a mild **effect. Applying 500 mg to rabbit skin caused moderate skin irritation. Diesel is a substance with a high boiling point, so the chance of poisoning from inhaling its vapors is low. Clinical manifestations: There have been reports of fine mist particles of air pollution around the tractor cab; continuous inhalation by the tractor driver for 15 minutes led to severe aspiration pneumonia. There have been reports of cases abroad in which acute renal failure occurred after cleaning both hands and arms with diesel for several weeks; kidney biopsies revealed acute tubular necrosis in the kidneys. Recovered after treatment. Therefore, it is necessary to consider that, after extensive skin contact, kidney damage may occur in some individuals. Contact dermatitis can occur upon skin contact, manifesting as erythema, blisters, and papules. When dealing with skin contamination, rinse immediately with soapy water and clean water. Treat symptomatically. Those who inhaled the mist droplets should immediately leave the area and go to fresh air. Oxygen is administered to those with symptoms. Antibiotics are given to prevent secondary infections when aspiration pneumonia occurs. Treat symptomatically.