Quality assurance  
  About oil products  
  1. Differences among fully synthetic oil, semi-synthetic oil and mineral oil.
    Fully synthetic oil:


Also known as synthetic base oil, fully synthetic oil is manufactured using synthetic compound oil generated through chemical reactions of ester or synthetic hydrocarbon compounds blended with additives. Fully synthetic oil has such characteristics as anti-oxidation, good fluidity at low temperature, high viscosity index, low volatility and high-temperature stability for optimal effects even under conditions of rough driving habits or high engine load.
    Semi-synthetic oil:
Semi-synthetic oil is manufactured using the base oil obtained by blending mineral oils and synthetic oils at a certain proportion blended with additives. Semi-synthetic oil has stable chemical molecular superior to those of mineral oils and supplements two different base oils with respective advantages so that semi-synthetic oil delivers more practical effects.
    Mineral oil:


Mineral oil is manufactured using mineral base oil (obtained through fractional distillation of crude oil) blended with multiple additives. Its main component is hydrocarbon compound. The chemical molecular structure of mineral oil is weak. Its fluidity at low temperature, high-temperature anti-oxidation performance, volatility and viscosity index are inferior to those of synthetic oil, but mineral oil is sufficient for general driving conditions.
  2. Differences between diesel and 92/95/98 lead-free gasolines.
  Octane number is used to display the shock-proof capability of engine combustion of the vehicles. The higher the octane number, the stronger the shock-proof capability, which means stronger capability to inhibit engine shock/explosion. However, it shall be used in combination with the compression ratio of the engine. That is, high compression ratio engines require high octane number gasoline to withstand higher pressure and temperature so as to avoid affecting the driving performance of the vehicles, damage of the engine due to shock and explosion and reduce the content of CO in the exhaust.
  In the past, lead was added as shock-proof agent to enhance the octane rating of gasoline and such gasoline is known as leaded gasoline. In recent years, new refining technologies are available to enhance the octane rating without adding lead and lead-free gasoline is borne. Also, 92/95/98 have special meanings and are related to their shock-proof capability in simple terms. Hence, it is advised to select manufacture-recommended gasoline. The octane number of gasoline chosen for vehicles must exceed that recommended by the manufacture.
  The operating principle of a diesel engine is different from that of a gasoline engine. The gasoline engine ignites using the spark plug to generate power while the diesel engine ignites through compression to explode. Like gasoline, diesel is also obtained through the fractional distillation or cracking of crude oils and depending on the source, diesel may be classified as primary diesel obtained through fractional distillation of crude oil and cracking diesel is obtained through the cracking of heavy oil.
 (1) The ignition point of diesel is higher than that of gasoline. The diesel engine explodes at high pressure to ignite the diesel.
 (2) The diesel engine has no spark plug.
 (3) As the stroke of the diesel engine is long, its torque explodes earlier and is higher.
 (4) The injection oil pressure of the diesel engine far exceeds that of the gasoline engine. As the particles of diesel are large, its combustion
   performance is inferior to that of gasoline.
 (5) The heat efficiency of the diesel engine far exceeds that of the gasoline engine (the compression ratio is generally higher than 17:1)
 (6) The service cycle/mileage of the diesel engine is longer.


What are API and ACEA? What is the Differences between the SL and SJ series products?

    (1)American Petroleum Institute (API)
Founded in 1919, API is an organization that develops standards for the selection and identification of the quality of gasoline/diesel engine oils. API has been joined by more than 400 members, most of whom are engaged in manufacture, refining and sales and co-establish the oil product performance standards. The standards fall into 2 categories: standards for commercial oils, e.g. motor oils for medium-to-large sized trucks, buses and engineering vehicles, which generally burn diesel for fueling, and standards for machine oils sold by general service stations, which are generally used for cars and the small cars with gasoline engine are represented by letter pairs beginning with S, for instance, SF, SG, SH, SJ and SL. Oils products certified by API may be marked with API’s dual ring sign on the bottle of the machine oils (for details, see About Oil Products). The levels of oil products are divided primarily depending on the low temperature fluidity, high-temperature cleanness, diffusion/filtering, oxidation stability, abrasion resistance, corrosion resistance, rust-resistance, catalyst compatibility and environmental protection requirements. Presently, SL is the latest level. S stands for gasoline engine and the letter after S stands for the level. Letters such as SJ/CF are also available on the bottles of gasoline available in the market. C after the slash stands for diesel engine. For grading, the latter alphabetically ordered ones refer to higher grades.
    (2)Association des Constructeurs Europeens (ACEA)
As a result of the restructure of plenty of auto manufacturers in Europe, original CCMC standards/specifications are replaced by ACEA standards/specifications starting from January 1996. In the past, as long as a manufacture has set up a plant in Europe, it may join CCMC and participate in certification. Now, it is strictly required that a manufacture can join ACA and participate in certification unless it manufactures vehicles in Europe. In the ACEA system, letters in pairs are used to identify the levels.
  4. API Motor Oil Guide


  API classification marks and certification marks are provided for the selection and identification of the quality of engine oils of gasoline/diesel vehicles; API marks are oil performance requirements jointly developed by international manufacturers, engine manufacturers and lubricating oil manufacturers. Presently, more than 500 companies around the world have participated in the sampling test activities performed by API in the market from time to time voluntarily to ensure the credibility of API marks.

1. Defining the performance level of oil product

2. Defining the viscosity of oil product

3. Fuel efficiency labeling



Performance Levels

Gasoline engine oils
(Applicable to small gasoline buses, tourism buses and light duty trucks): API represents motor oils specially designed for gasoline engines with letter pairs beginning with S (from service station), which have developed from original SA, SB to the presently highest level.

Diesel engine oils
(Applicable to heavy duty vehicles, trucks and general diesel vehicles): API represents motor oils specially designed for diesel engines with letter pairs beginning with C (from Commercial), which have developed from original CA, CB to the current CF, CF-2, CF-4, CG-4, CH-4 and CI-4.


Namely the viscosity and fluidity exhibited by motor oils at particular temperatures. Pay attention to the special needs of your vehicle and choose the SAE viscosity level of motor oils in accordance with the requirements of the manufacturer for your vehicle.


Fuel efficiency labeling
The fuel efficiency marks are used to small gasoline buses, tourism buses and light duty trucks. Generally, if a country can use fuel efficient motor oils extensively, the effect of fuel saving may be achieved (the viscosity mainly ranges between SAE 5W/30 and 10W/30).


When you are purchasing a motor oil, check if it bears the following API quality marks?

API classification marks
API certification marks
The performance level, viscosity and fuel efficiency capability of the oil products.
The oil products conform to ILSAC standard.
SAE Viscosity Guide for Choosing Motor Oils
The most suitable motor oil viscosity for the climate in Taiwan is 10W/40 or 15W/40 for summer and 10W/30 & 10W/40 for winter. Note: The requirements of your vehicle may vary. Please select motor oil viscosity according to the recommendation of the vehicle manufacturer.
Applicable SAE viscosity level



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