ENGINE OILS

Steel Shield automobile lubricants with ABF Technology is the ultimate choice for your engines, transmissions and any movable parts of your vehicles. Many other premium oil brands in the market contain ester, even molybdenum and other unknown additives which can cause adverse effects or even damage your engine after prolonged usage. Steel Shield is totally different, it is made of the latest lubrication technology in the world - Electrochemical Ionization. It has been proven to be fuel economic and able to boost the power of your engine to an entirely high level. See our Customers' Testimonies and SWRI Test Reports.

The "Must Know" Knowledge of Engine Oils

Inside an automobile engine, there are many forms of metal wears can occur: Metal sliding like ring & liner interface, gear teeth rollings, hydrodynamic lubrication of journal bearings, etc. Also, engine oils are subjected to a wide range of temperature regimes, such as cold start in winter and running at the highest temperature during high loading conditions in summer. The engine oil lubrication have 5 basic functions:

• Metal components lubrications: prevent metal-to-metal wears
• Transfers heat and cool down the engine
• Neutralizes the byproducts of engine combustion, prevent metal corrosion and oil degradation
• Clean engine components which prevent parts wears and ensure smooth running
• Sealing the engine components

Some engine lubricants contain additives which may be over 20% of the total oil content which are unknown chemicals. The lubricant itself must be able to prevent oxidizations. It's because when oil oxidizes, the oil molecular structure also changes. This affects both the oil and the additives, and reduce the efficiency of the lubricant or can even cause adverse effects to the engines. Though viscosity of the lubricant is of less concern when Steel Shield ABF Technology is activated, it’s important to note that the viscosity of the lubricant will increase when the basestock degrade, and that will cause excessive sludge formation and acids which can damage metal surface and cause metal wears.

For these reasons, it is recommended that only use high quality engine lubricants which meet the right API engine classifications and SAE viscosity ratings. The following table reviews the functions of the additives:

Classifications of Engine Oil Viscosity

The letter "W" stands for winter, including some cold weather conditions. In the following table, the cold start performance measurements are shown in the second and third columns. In the second column, it revealed the criteria of cold performance which the W grades must meet, as measured in a "high shear test" known as the "Cold Cranking Simulator" (CCS), or ASTM D5293. Each grade has a viscosity target in centipoise which it has to meet. This viscosity is arbitrarily the highest viscosity which will allow the engine to run over fast enough (use an average of 75 rpm) to allow it to start. For example , the "15W" has to meet the viscosity (7000 centipoise) at -20℃ maximum. The "10W" has to meet the viscosity of target at -25℃, and "0W" oil at -35℃. Therefore, a "10W-XX" oil is formulated to enable the engine to start with adequate protection against metal wears at -25℃ while the minimum start temperature of a "5W-XX" oil is -30℃.

Some lubricants are able to allow startup at the design temperature (the oil is easily sheared), yet once the engine is running, the oil will not flow in to the pump inlet. To prevent lubricant which could do that from being marketed, in 1980's, the SAE added the third column which defined the lubricant's performance under "low shear" conditions. The MRV (Mini rotary viscometer) test assures that there is a 5° range between the lubricant's starting temperature, and the minimum temperature that oil will flow to the oil pump. This is an important feature as the instance oil flow during startup can reduce engine wears dramatically. According to statistics, over 70% of metal wears of lubricated components occurs at startup.

The minimum and the maximum viscosities of the lubricants are shown in the fourth column which are the operating temperatures of engines. These kinematic voscisity tests measure flow resistance of lubricants. There is a viscosity range for each grade (e.g. for a monograde "20": from 5.6 cSt to less than 9.3 cSt). Notice that the monograde "30" oil will be much thicker at the colder temperatures than the "multigrades" because the multigrades have a lower viscosity under cold temperatures. The multigrade lubricants achieve those ability by modifiying the viscosity index (the rate of change of the viscosity under temperature changes) by blending polymeric thickeners such as viscosity modifiers or viscosity index improvers. Lubricants using synthetic PAO (Poly Alpha Olefin) basestocks are natural multigrades.

The advantages of using multigrade lubricants are better low temperature cold-start performance and oil flow, while providing adaquate viscosity at high operating temperatures. That is, a wider temperature range.

Fig.1 - Viscosity Of Engine Oils

In addition, the HTHS (High Temperature, High Shear Viscosity) test evaluates the load carrying capability of the lubricant under high shear, high pressure conditions at 150℃. It simulating the lubricants capability at maximum stress in the engine. Most engine manufacturers publish minimum specifications for this criteria.

The API Engine Service Classification

The API Engine Service Classification was established in 1970 by the American Petroleum Institute (API), the American Society for Testing and Materials (ASTM) and the Society of Automotive Engineers (SAE). This certification scheme is based on the engine tests and defines the performance level required by different lubricants. In this system, it includes "S" (means "SERVICE", or think about "Spark Ignition") Classifications covering gasoline engines, and "C" (means "COMMERCIAL", or think about "Compression Ignition") Classifications for diesel engines. It permits additions of new categories in order to meet new engine operation requirements. Notice that obsoleted categories must not be used as part of the API "Donut" symbol on the containers after a certain allotted time.

The updates and modifications of the Classifications are mainly caused by the controlling of diesel engines emissions and gasoline engine fuel economy requirements. The US EPA diesel emissions restrictions are increasing, but the vehicle manufacturers are keen on satisfing the "Corporate Average Fuel Economy (CAFE) limits. The development and research of new automatic transmission fluids and gear lubricants are aslo driven by the fuel economy requirements.

In diesel engines, the permissible particulate (soot) and nitrogen oxides (main cause of smog) emission levels is lowering year after year. High temperatures are required to reduce the soot levels, but it will increase the nitrogen oxides levels at the same time. The Exhaust Gas Recirculation (EGR) technology can recirculate exhaust gases to the combustion chamber while the Diesel Particulate Filters (DPF) can eliminate particulates in the exhaust gases. However, those technologies can lead to higher soot loading of the crankcase oil and higher acidic (and others) contaminations in the lubricant. Advanced lubricants must be developed to tackle those issues in new engines and should also be compatible with older engines. The Selective Catalytic Reduction (SCR) is also the latest technology to reduce NOX emissions by using urea injection. The up-to-date APE Classifications and their applications can be reviewd from the following document (source: the API Official Website):

Important: Why API Certification Is Not Necessary?

The API Engine Service Classification Certifications is not a necessary criteria in engine lubricants selections, reasons are as follows:

1. It is not a guarantee for the lubricant manufacturers
2. It is not a guarantee for the products (lubricant)
3. It does not mean it agrees the formulations of the lubricants
4. It only proved the lubricants conformed to certain specifications, but it has no guarantee on the performance
5. A lubricant does not have this API Certification (or "Donut" symbol) does not mean it cannot meet the API standards. Many lubricant manufacturers whose lubricants can meet the API Standards but do not apply for the API Certifications simply because they want to save unnecessary annual costs