1.How to distinguish diesel oil?
There are two codes for the quality grade and specification of diesel oil:
American Petroleum Institute (API) quality grades: CA, CB, CC, CD, CE, CF, CF-4, CG-4, CH-4, used to show the comprehensive performance of oil products in preventing oxidation, resisting wear and wear, controlling emissions, saving fuel, etc., from left to right, the higher the grade, the better the performance.
American Society of Automotive Engineers (SAE) viscosity grade: OW, 5W, 10W, 15W, 20W, 25W, 20, 30, 40, 50, used to show the viscosity of diesel oil, the higher the value, the greater the viscosity, with W is used in winter low temperature oil, multifunctional oil such as: 5W-50, 10W-30, 15W-40. It is the most characteristic aspect besides API and SAE, indicating the technical content, quality assurance, practical surface and related services of an oil product.
2.Table of multi-grade oil viscosity grade and operating ambient temperature range:
| viscosity grades | Ambient temperature | Applicable season | Applicable regional |
| 5W/30 | -30~30℃ | Four Seasons general | Northeast 、North、 Northwest |
| 10W/30 | -25~30℃ | Four Seasons general | North、 West |
| 10W/40 | -25~40℃ | Four Seasons general | North、 West |
| 15W/40 | -20~40℃ | Four Seasons general | North、 West |
| 15W/50 | -20~45℃ | Four Seasons general | South of Yellow River and Yangtze River |
Higher API level, not lower than diesel engine and machinery manufacturers requirements. The higher the level, the better to protect your diesel engine; Even lower-grade diesel engines can benefit from higher-grade diesel oil.
3.What kind of diesel oil should I choose?
For the most appropriate SAE viscosity, try to choose the viscosity level recommended by the diesel engine and mechanical manufacturer. If you have difficulties, you can choose products that include the viscosity recommended by the diesel engine and mechanical manufacturer. For example, if the manufacturer recommends 10W-30, you can choose 10W-40 or 5W-50.
4.Why use a special oil?
As we know, if the oil is not chosen properly, it will very easy to have excessive carbon accumulation and exhaust in the diesel engine, causing the diesel engine wear, and even causing the failure of the cylinder. Nowadays, there are many diesel oil brands with great quality difference, many lubricating oil grades, and various diesel oil requirements have their own characteristics, so how to correct choose oil is a problem that users feel very concerned.
In order to serve users better, Shanghai Diesel Engine Co., Ltd. from January 2003 began to use all special oil. The special engine oil is a diesel engine oil blended by a carefully selected supplier and evaluated by a variety of rigorous tests. Special oil unified certification, unified marking, unified packaging, unified price, to ensure that users use high quality diesel oil, to ensure the interests of users. Shanghai Diesel Engine Co., LTD. 's designated supplier is Sinopec Great Wall Lubricating Oil Group Co., LTD., which is a leading supplier of diesel engine oils in China with excellent performance, stable quality and high market share.
5.Why do Marine diesel engines use lubricating oil?
There are five main functions of Marine diesel oil : ① lubrication and friction reduction, friction pay parts of the diesel engine such as cylinder wall and piston; Crankshaft, connecting rod, camshaft and bearing bush; Tappet and rocker arm for lubrication and friction reduction. ② Cooling function of diesel engine components. ③The function of sealing combustion chamber. ④Keep the lubrication parts clean. ⑤Anti-rust and anti-corrosion effect.
6.Is it possible to change and use different grades and grades of oil frequently in a diesel engine?
The likelihood of problems occurring is high. Because different grades, different grades of internal combustion engine oil, the composition of the formula is not the same, if they are incompatible, it will produce reaction, precipitation and so on, it is not good for the diesel engine. Therefore, the diesel engine oil must be strict and careful, relatively fixed, do not frequently change different grades and grades of oil, avoid damaging the diesel engine.
7.Is the viscosity of diesel oil more greater is more better?
The viscosity of diesel oil is not more greater is more better. The diesel engine starting wear accounts for two thirds of its total wear. The viscosity of lubricating oil is higher than the requirement. When the diesel engine starts,it needs more time to take that lubricating oil to reach the friction parts, The starting wear of diesel engine is increased. So the idea that the greater the oil viscosity, the better is incorrect.
In addition, the greater the viscosity, the internal friction resistance between the oil is also large, the increase in power loss, the thermal load and mechanical load of the diesel engine is also increased accordingly, the lubrication of high-grade diesel engine oil is improved by adding oil additives and extreme pressure additives in the lubricating oil to solve. Studies have shown that the viscosity of lubricating oil decreases by one unit at 100℃, and the fuel can be saved by 1.5%. Reduce fuel consumption by using lubricants with low viscosity.
8.Is the diesel cooling system colder is better?
High diesel engine temperature will accelerate the deterioration of the oil, produce oil sludge, carbon accumulation, resulting in oil film easy to break, poor lubrication, wear intensified. So the diesel components must be cooled to keep the diesel engine working normally. But if the cooling is too much, it will also produce negative effect, which is bound to increase the heat loss of the diesel engine, resulting in the decrease of effective power. At the same time, the diesel engine temperature is too low is not conducive to the formation and combustion of combustible mixture, oil viscosity increases, friction loss increases, will also make the diesel engine power decline. Practice has proved that the diesel engine temperature is too high or too low is not good for the diesel engine work. Therefore, the purpose of cooling is to make the diesel engine in operation get moderate cooling, so as to keep working in the most suitable temperature range. Generally, the cooling water temperature in the cooling jacket of the cylinder head in the water cooling system should be between 80-90℃.
9.What kind of diesel oil do you want to change in winter?
It is cold in winter,so in this season, the viscosity of oil will increase with the decrease of temperature, thus causing difficulties in the cooling and starting of the diesel engine, and the wear caused by the diesel engine during starting is more than twice as much as usual. At this critical moment, it is required that the oil viscosity is small, and the speed from the oil tank to the diesel lubrication point must be fast, good oil should be quickly pumped to the diesel lubrication part within 1 second of ignition, even in the low temperature of minus 20 to 30 degrees, still can provide the best protection for the diesel engine.
10.Why can't there be too little or too much diesel oil in the crankcase?
When filling the crankcase of diesel engine with lubricating oil, the oil level must be between the upper and lower limit of the oil ruler according to the manufacturer's regulations, which means that the oil level shall not exceed the upper limit of the oil ruler, nor lower than the lower limit of the oil ruler. Some users always think that more oil is better than less. Actually otherwise, if the oil is too much, it can make the most of the crankshaft and even whole bubble in the oil, this is not only increase the crankshaft rotates resistance, increase the consumption of diesel engine internal power, output power is reduced, but also can make the wiggle of lubricating oil into the combustion chamber to burn in great quantities, blue smoke coming from the exhaust, increased consumption of lubricating oil, the diesel engine fault increases, and can't work normally. If the lubricating oil is too little, the oil level is lower than the lower limit of the oil ruler, it is easy to cause the oil pressure to be too low, not up to the lubrication requirements, easy to produce life cylinder, or even burning tiles, holding shafts and other malignant accidents.
11. Is the viscosity of the oil better?
The higher the oil viscosity, the better the diesel engine.
The starting wear of diesel engine accounts for two thirds of the total wear. When the viscosity of lubricating oil is higher than the requirement, the longer the time it takes for the lubricating oil to reach the friction parts, the greater the starting wear of diesel engine. Therefore, the idea that the higher the oil viscosity, the better is not correct. In addition, the higher the viscosity is, the greater the internal friction resistance of the oil on the friction surface is, and the power loss is increased. The thermal load and mechanical load of the diesel engine are also increased correspondingly. The improvement of the lubricity of medium and high-grade diesel engine lubricating oil is solved by adding oil-based additives and extreme pressure additives into the lubricating oil. Studies have shown that the viscosity of lubricating oil decreases by 1 unit at 100 ℃. The fuel can be saved by 1.5%. That is to say, the use of low viscosity lubricating oil can reduce fuel consumption.
12.If the oil is not changed on schedule, what are the problems? How to determine the oil change period?
If the oil is not changed on schedule, the wear resistance of the oil to the diesel engine will be significantly reduced. The oil is mixed with sludge, carbon, water, acid, and incomplete combustion products from fuel combustion. At the same time, the additives in the oil will be used with the continuous consumption, affect the performance of the oil. Changing the oil will not only remove pollutants, but also ensure that the oil content is kept at a reasonable level.
How to determine the oil change period? Because of the design of the engine is different, it is suggested to determine the oil change period according to the diesel engine maintenance manual. It is also necessary to consider the degree of old and new diesel engine and the use of the environment to make appropriate changes.
