Gasoline is a special fuel applied in combustive engines. It is generally water-white transparent in nature with the density between 0.71-0.75g/cm3 and a unique aromatic smell. It can be divided into aviation gasoline and automotive gasoline, which is sold in service stations. The current specification for petroleum products is GB 17930-1999 “lead-free automotive gasoline” under which there are 90#, 93# and 95# gasoline. The specification of 97# and 98# gasoline is in line with enterprise specification. The automotive gasoline is categorized based on research method octane number.
Gasoline Performance Needed for Automotives:
1. Anti-explosion
2. Evaporation
3. Anti-dioxide and Stabilization
4. Anti-corrosion and environmental requirement
Items to be examined in terms of gasoline quality are as follows:
Gasoline octane number is supposed to be compatible with the compression ratio of the engine. If the engine with high compression ratio is applied with low octane number gasoline, the engine tends to knock, which will cause malfunctions like piston sintering and piston ring breakage and impairment to engine parts. If engines with low compression ratio is applied with high octane number gasoline, the ignition timing will be altered, which will cause incremental sedimentation inside the engine cylinder thus shortening engine life. Gasoline numbers recommended by China Automobile Industry Society and China Environmental Protection Industry Society for domestic and foreign brand cars are listed in the form below:
Diesel is a special fuel for compression ignition engine (i.e. diesel engine). Diesel, appearing water-white, light yellow or dark brown, is divided into light and heavy diesel. Light diesel is applied in high-speed diesel engines with a speed above 1000r/min while light diesel is applied in low-speed and mid-speed engines. Diesels sold in service stations are light diesels. The current specification for light diesel products is GB252-2000 “light diesel”, under which diesels are categorized into 10#, 5#, 0#, -10#, -20#, -35# and -50# based on condensation point of diesels. The recommended specification of GB/T 19147-2003 for automobile diesels is issued on May 23rd, 2003 and will be implemented on October 1st, 2003.
Requirements on Light Diesels for Diesel Engine:
Due to the fundamental difference between working process of diesel engines and gasoline engines, the quality requirement for diesel is different from that of gasoline as well, specifically:
1. Good combustibility
2. Good low-temperature mobility
3. Appropriate evaporation
4. Good stability
5. Appropriate viscosity
6. Good anti-corruption performance
Items to be examined in terms of diesel quality are as follows:
Cetane value, oxidization stability, sulfur content, color, acidity, ash, copper sheet corrosion, solidifying point, cold filter plugging point, flashing point and distillation range, etc.
How to Choose Light Diesel:
The following principles need to be conform to in selecting diesels according to requirements of the GB252-2000 specification:
1. 10# light diesel is compatible in diesel engines with preheating units;
2. 5# light diesel is applicable in areas where the risk possibility is 10% and the lowest temperature is above 8¡æ;
3. 0# light diesel can be applied in areas where the risk possibility is 10% and the lowest temperature is above 4¡æ;
4. -10# light diesel is applicable in areas where the risk possibility is 10% and the lowest temperature is above -5¡æ;
5. -20# light diesel can be applied in areas where the risk possibility is 10% and the lowest temperature is above -14¡æ;
6. -35# light diesel can be applied in areas where the risk possibility is 10% and the lowest temperature is above -29¡æ;
7. -50# light diesel can be applied in areas where the risk possibility is 10% and the lowest temperature is above -44¡æ;
