The quality of motor oils is defined by a complex combination of letters and numbers. These will be explained as follows. The correct oil for your car can be identified by our oil guide.
API CLASSIFICATIONS
The American Petroleum Institute (API) has laid down the quality requirements and test criteria for motor oils worldwide. S stands for Gasoline and C for diesel engines. The next letter denotes the issue of the classification. API-SN is currently the latest and highest quality grade for gasoline engines.
ACEA SPECIFICATIONS
The ACEA (Association des Constructeurs Europ?ens d?Auto mobiles) has been the official successor to the CCMC since 01.01.96. This organization defines the quality of motor oils according to European specifications. The ACEA classificatons use the abbreviations A1, A2, A3 and A5 for passenger vehicle gasoline engines. The abbreviations B1, B2, B3, B4, B5 apply to passenger vehicle diesel engines. There are so-called Low SAPS or Mid SAPS oils for passenger car gasoline and diesel engines with exhaust gas aftertreatment, e.g. soot particulate filter, as per Euro 4 standard or higher. These oils also carry the designations C1, C2, C3 or C4. The abbreviations E2, E3, E4, E5, E6, E7, E9 apply to diesel engines in commercial vehicles and working machinery. The additional number indicates performance criteria.
EURO 4/5 STANDARD
The Euro IV emissions standard has been in effect as of January 1, 2005. The Euro V standard is in effect throughout Europe for passenger cars since September 1, 2009. This means that the emissions from diesel engines must be reduced by up to 57 percent.
Complying with this new standard not only re quires technical modifications to engine technology or exhaust gas aftertreatment systems; the mineral oil industry also has been commissioned to develop new lubricants. To this end, LIQUI MOLY has engineered ?TOP TEC
4xxx?, lubricants specially designed to comply with the new emissions standards. Daimler , VW, BMW and Opel for example, prescribe mandatory use of such lubricants for their diesel-powered vehicles equipped with a soot particulate filter.
COMPANY APPROVALS
Different vehicle manufacturers place additional requirements on motor oils: for example, Mercedes-Benz ? Sheets 228.1, 228.3 228.5 and 228.51 for commercial vehicle diesel engines and 229.1, 229.3, 229.31, 229.5 and 229.51 for passenger vehicle gasoline and diesel engines; VW: Out-of date VW Standard 500 00 already withdrawn, VW Standard 501 01 is the standard for gasoline engines, VW Standard 505 00 for diesel engines with exhaust-gas turbocharging, 505 01 for diesel engines with pumped-jet injection systems and VW
Stand ard 502 00 for gasoline engines with enhanced performance. All VW standards named require a change interval of a maximum of 15,000 km or, for low mileage drivers, an annual oil change interval. VW Standards 503 00 / 506 00 / 506 01 are valid for gasoline engines, diesel engines with and without pumped-jet injection as well as extended maintenance intervals (WIV) as of model year 2000. For pumped-jet engines with extended maintenance intervals (WIV), the standard 506 01 came into effect starting 5/2001. A Standard 506 01 lubricant is currently mandatory for R5 and V10 TDI engines up to manufacture year June 2006. All other engines can be filled with Standard 504 00 / 507 00 oil (LIQUI MOLY TOP TEC 4200). With this motor oil, oil change intervals of up to 50,000 km are possible as per the manufacturer?s specifications. The oil change must how ever be performed after 2 years, at the latest (see manufacturer?s specifications).
VISCOSITY
is the measure of the internal friction of a fluid. It depends very strongly on the temperature and is classified by the SAE committee (Society of Automotive Engineers) into a number/ letter combination (e.g. 5W-40). The reference number (e.g. 5W = winter) is the code for the behavior at low temperatures while the reference number (e.g. 40) is the code for the flow properties at high temperatures (100 ?C). The operating life of an engine depends substantially on the basic oil used, and also on the viscosity of the motor oil. Whether the oil takes 2.8 seconds to reach the last lubrication point of the engine at low temperatures in the case of 0W-XX oils or 48 seconds in the case of 15W-XX oils has a decisive influence on the engine?s operating life.
ADDITIVES
Additives are chemical agents which are added to oils to improve existing properties or to add new properties. Antioxidants, for example, improve the ageing stability of the oil, wearprotection additives protect the engine from high levels of wear and cleaning additives loosen and remove harmful deposits inside the engine. Different types and amounts of additives are added to the oil depending on application and required performance capabilities. In technical jargon, the oils are said to be ?blended? or ?doped?. The proportion of additives in a modern motor oil can range from 15 ? 30%.
MINERAL MOTOR OILS
Motor oils are conventionally made from mineral oils. In view of the increased demands for extended intervals between oil changes, high
engine performance and low friction properties, etc., the performance of these oils is limited. Typical viscosities are: 10W-40, 15W-40 and 20W-50.
HYDROCRACK (HC) MOTOR OILS
Hydrocrack oils are mineral base oils which have been further processed at the refinery using elaborate methods. They also contain a small proportion of synthetic components. Typical viscosities are: SAE 5W-40, 5W-30 and 10W-40.
PARTLY SYNTHETIC MOTOR OILS
These are mineral oils with synthetic components. They improve the coldstart properties, keep the engine clean and provide outstanding wear protection. Typical viscosities are: 10W-40 and 5W-40.
FULLY SYNTHETIC MOTOR OILS
Valuable Synthetic fluids are the basis of up-to-date high performance motor oils. Fully synthetic motor oils can be used for gasoline and diesel engines, provide excellent oil delivery during cold starting and optimum wear protection, have friction-reducing properties and keep the engine outstandingly clean. They frequently comply with the highest quality standards of the API, ACEA and companyspecifications. They are particularly suitable where there are long intervals between oil changes. Typical viscosities are: 0W-30, 0W-40 and 5W-40.
DIESEL MOTOR OILS
Currently, the ACEA B3 or B4 classifications represent the highest requirements on passenger vehicle diesel and turbo charged diesel engines. They are most suitable for use in aspirated and turbocharged diesel engines with and without charge-air cooling. These requirements are only satisfied by high-performance motor oils such as LIQUI MOLY DIESEL HIGH TECH 5W-40.
LOW FRICTION OILS
These have good cold-flow properties and are characterized by low pumping work requirements and are capable of high thermal loading. They therefore have a beneficial effect on the fuel consumption. Typical viscosities are: 0W-30, 0W-40, 5W-40, 5W-30 and 10W-40.
YEAR-ROUND OILS
In a mild climate, year-round or multigrade motor oils can be used throughout the year. They do not thicken during the winter and they are not too thin at high engine temperatures ? for example, 0W-30, 0W-40, 5W-30, 5W-40, 10W-40, 15W-40 and 20W-50.
MoS2 LOW FRICTION
MoS2 (molybdenum disulfide) forms a thin layer of high load-bearing lubricant on surfaces exposed to friction and on sliding parts in the engine. The excellent low friction properties of this material lead to lighter engine running, thus inhibiting wear and preventing breakdowns. Results from scientific tests have shown that MoS2 reduces fuel and oil consumption and leads to significantly less wear in the engine. MoS2 Low Friction is available from LIQUI MOLY as an oil additive (added to the motor oil) or as a ready-prepared MoS2 low friction motor oil. In spite of all efforts to polish the surface of the metals mechanically, they still look rough under the microscope (1). This rough ness is made smooth by applying a film of MoS2 lubricant (2) and this ?surface finish? reduces frictional resistance and decreases wear.