Yes I think it was over 8 yrs ago that Germany specified that synthetics had to be PAO however believe that has changed they also consider group III to fall in the same category. Here is a German compound blender advertisement I found in the net notice how they claim "strict adherence to purity laws but then also accept Grp III.
BIZOL’s new and innovative motor oils meet and exceed the standards of the German automotive industry based on highest quality standards with 100% consumer transparency and protection.
Outside of Germany, partial Synthetic Motor Oils can be labelled as Fully Synthetic Motor Oils. This is not allowed in BIZOL because according to German Law we need to clearly label Fully Synthetic and Partial Synthetic motor oils. In essence, BIZOL’s Synthetic Motor Oils have the highest German quality standards with 100% consumer transparency and protection.
What is synthetic oil:
As the name implies, synthetic oil is made with products that are chemically manufactured. These products, primarily polyalphaolefins (PAO) and esters, possess many of the same qualities as crude oil but without its disadvantages. The chemical processes permit tight control of the molecular structure of PAOs and esters, ensuring the final oils have uniform and stable properties.
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.
Conventional lubrication oil is simply refined crude oil of a certain viscosity range that has been blended with an additive pack to meet the U.S. API specifications or, alternatively, the European ACEA specifications. Conventional oil contains a mixture of hydrocarbon compounds that all have different properties. These include paraffin chains and cycloparaffins that form the basis of the lubricating oil as well as volatile aromatics that are chemically reactive and form black sludge. Other impurities include waxes and a number of compounds containing nitrogen and sulfur. It is the presence of the aromatics, waxes, and other impurities that limit the service life of mineral oil and contribute toward engine wear.
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.
They include the following statement "Synthetic oils, whether manufactured synthetically or derived from highly refined API Group III base oils,"
Here is a good article on this subject.
The Basics of Synthetic Oil Technology
The take away here is majority of modern engine oils that are API certified use at least GRP II now those Vis-grades that start at 0W that is more than likely API Gp III , PAO or a blend of both or even partial blend with group II base stock.
Like I said earlier Shell GTL is the monkey wrench because it's not made from crude or even severely hydrocracked / hydro-processed because it's made from methane gas so that is another synthetic but it doesn't fall under Base stock category IV or V. Why we'll these categories were standardized years prior.
ossible increase in fuel economy but the best normally recorded with statistcally relevant data is at best 2-3%, any thing higher is questionable
