Strictest German quality standards for Synthetic Oils
Synthetic oil was developed before the Second World War and saw widespread use in Germany. The invention of the jet engine with its high engine temperatures opened the way for the first wide scale use of synthetic oils outside of wartime. Meanwhile, development of automotive oils continued, and in 1975, the first commercially available synthetic motor oil was launched.
Since then, and in response to the need for better performing oils, the use of synthetic oils has increased and many auto manufacturers now require the use of synthetic oil in engines.
Strictest German quality standards for Synthetic Oils
What is Synthetic Oil?
However, some synthetic oils are made from highly refined crude oil. A process known as severe hydrocracking breaks the long chain hydrocarbons into shorter, more uniform molecules and at the same time reduces the level of impurities in the oil. The oil produced, known as API Group III oil, has almost identical properties to synthetic PAO oil and in the U.S. is regarded as synthetic. In Germany, it is often referred to as HC synthesis oil.
Synthetic oil is an effective substitute for normal refined lubrication oil and has superior lubricating properties, is longer lasting, and is a better choice for modern engines.
Synthetic oils, whether manufactured synthetically or derived from highly refined API Group III base oils, contain a smaller variety of compounds with little variation in their properties. The level of impurities present in these oils is lower than that found in mineral oils.
Due to the negligible quantities of impurities, synthetic oils exhibit far more stable properties than mineral oils, and to a large extent, their service life is only limited by the life of the additive packs. Synthetic oil offers better engine protection than mineral oils in terms of heat, cold, wear, and sludge buildup.
Crude base oils are divided into three groups. API Group I base oils are produced using a solvent refining process that produces a relatively poor base oil containing at least 10 per cent aromatics and over 300 parts per million (ppm) of sulfur. Initially, these API Group I base oils formed the basis of most lubricating oils.
API Group II oils were developed in the 1950s after it was discovered that hydro treating crude oil above 600 ºF (315.6 °C) in the presence of hydrogen removed impurities and stabilized the reactive aromatics. The oil is subsequently hydrocracked at high pressure followed by a dewaxing process. Group II oil has lower aromatic levels and contains less than 300 ppm sulfur. API Group I and II base oils exhibit the same viscosity index range of 80 to 120.
Esters, made from an oxoacid reacted with a hydroxyl compound such as alcohol or phenol, belong to API Group V base oils and have excellent lubricity and high temperature resistance. They are more expensive than PAOs and not commonly used as the base oil for synthetic motor oil but rather as an additive. However, ester oils were the basis of the first jet engine lubrication oils and are still used as such due to their thermal resistance to temperatures of 400 ºF while retaining the ability to flow at very low temperatures.
Synthetic oil generally has a lower pour point so needs lower levels of pour point depressants than conventional oils, which have high levels of waxes that solidify at low temperatures.
The lower levels of aromatics also benefits the oil as lower levels of sludge dispersants are required. One additive that is necessary is a seal conditioner to ensure seals retain their elasticity and do not dry out, and additives are also needed to disperse products of combustion such as soot.
Overall, the additive pack requirements are much reduced and synthetic oils are suitable for long service life.
Synthetic oils, albeit more expensive than conventional oils, are significantly better virtually in all aspects. The conventional point of view espoused by many mechanics that it is best to change standard motor oils frequently no longer applies as longer lasting synthetic oil is likely to provide far better overall engine protection.
Specific measurable benefits of synthetic oils include cold cranking properties, low volatility, and oxidation resistance. In winter, the cold cranking viscosity of engine oil determines the lowest temperature at which an engine can be started. At minus 22 ºF (minus -30ºC) the cranking requirements of synthetic oils are nearly one third of Group II base oils. The Noack Volatility test measures the evaporation of oil at operating temperature, the consequence of which is an increase in oil viscosity and drag on the engine. Synthetic base oils have less than half the evaporation rate of Group II oils. Oxidation of oil determines how long the oil can be used, and a useful way to measure this is the Turbine Oil Stability Test. Synthetic oils perform much better than Group I and II oils.
Synthetic oils contain hardly any sulfur, unstable hydrocarbons, or other trace impurities. Consequently, the oil is stable in use and produces hardly any harmful deposits. The oil is free flowing, so it circulates immediately at startup, providing faster and better startup protection during the critical period when most engine wear occurs.
Modern synthetic oils are compatible with all engines, provide better engine protection, and improve performance due to their lower friction characteristics. Selection of the right synthetic oil is easy if simple guidelines are followed:
• Choose a viscosity rating as specified in the vehicle handbook.
• Verify the API or ACEA oil specification.
• Choose an oil with the same or higher API classification.
• For European vehicles, choose an oil that complies with the specific ACEA requirement. Especially for German cars it is advisable to use German motor oil.
• Check oil complies with any mandatory auto manufacturer oil specification requirements (these are usually shown on the oil container).
Provided the oil complies with the above requirements, it will be compatible. Bear in mind the use of synthetic oil is mandatory in many modern vehicles, especially turbo-charged models, and the use of non-synthetic oil could cause engine damage.
Synthetic motor oil provides the following benefits:
• Longer engine life
• Lower emissions
• Excellent winter performance
• Enhanced engine wear protection
• Minimal deterioration between oil changes
• Cleaner engines
Although synthetic oil costs more, by sticking to the oil change requirements for the vehicle instead of the usual 3,000 mile oil change intervals,(4,828 km) overall oil service costs are certain to be lower, and better protected engines will last longer.