Knowledge of vehicle-use lubricant selection principle - bearing

1, how to select the internal combustion engine oil ( 1) According to the characteristics of the internal combustion engine and vehicle, namely choose oil load and speed. Load of high speed low, for example, some large bulldozers, cranes, and drill, etc. , generally choose larger lubricating oil viscosity, such as SF40, CD50, light load of high speed, such as cars, jeeps, small power equipment generally choose sticky degree of lubricating oil, such as SG15W / 40, SF30, etc. ( 2) According to the internal combustion engine work hard. Such as diesel engine is a temperature higher than 230 - ring area - - - - - - 250 ℃, strengthening coefficient greater than 5, supercharged diesel engine oil with CD or more oil, such as CD40, SG/CD40, etc. Gasoline engine according to the compression ratio and whether there is a crankcase positive pressure ventilation, exhaust gas recirculation, and selection of engine oil such as catalytic converter, the compression ratio, the greater the selection of engine oil level is higher, with the above attachment, generally choose SG more oil. ( 3) Oil capacity and power ratio is also choose oil factor. Oil capacity and power ratio is also choose oil factor. Large capacity of the oil is not hard to product quality requirements, high quality demand of small oil capacity of oil. General European production engine is small in size, big power, requires the use of high quality oil, such as SHSJ. ( 4) According to the region, season, the temperature selected oil. Winter cold area, should choose low viscosity, low pour point oil or multistage oil, such as the northeast region in China, can choose SF10W / 30, SH5W / 30, etc. ; Higher temperature area throughout the year, such as hainan, guangdong, can choose the oil of high viscosity, such as SF40, CD50, etc. ( 5) According to the abrasion of engine oil. The new engine should choose smaller viscosity oil ( Considering energy saving) , and wear large, cylinder wall and piston clearance big engine should choose larger viscosity ( Consider seal) 。 2, how to select the gear oil ( 1) Automobile driving axle hyperbolic gears must choose GL - 4、GL— Level 5 oil, GL - 3 oil and old brand 18 #, # 24 hyperbolic gear oil should not be used. ( 2) According to the environmental temperature with different viscosity gear oil. Such as 75 w / 90 is particularly suited to the cold of winter; 80, the 85 w / 140 w / 90 oil in east China, central China, north China region general during summer and winter seasons, winter use of south China, southwest China; 90, 140, the general oil all over the country the summer, winter in south China is available. ( 3) According to vehicle load conditions performance levels. GL— 4 is suitable for middle and low load vehicles, GL - 5 suitable for heavy duty vehicles. ( 4) Car manual transmission requires the use of gear oil, general use 80 w / 90 or 85 w / 90 oil, it is best to use GL - 4、GL— 5 oil level.