bought from watford yesterday but believed (told) nationwide, looking at the codes on container this is a good spec oil. very good price for a fully synthetic oil.
The first real synthetic engine oils appeared for aircraft engines in World War II concurrently in Germany and in the United States. The motivation in Germany may be primarily related to resource issues, but also to functional performance requirements. The base oils for aircraft engines in Germany were based on a blend of an adipic acid ester with a poly(ethylene) oil e.g. polymerized olefins/ethylene. Easing engine starts in winter and avoiding soot deposits in the oil radiator were two of the drivers for the U.S. Air Force, to adopt polyglycols (polypropylene glycol monobutylether) starting in March 1944.
The technical advantages of synthetic motor oils include
Measurably better low and high temperature viscosity performance
Better chemical & shear stability
Decreased evaporative loss
Resistance to oxidation, thermal breakdown and oil sludge problems
Extended drain intervals with the environmental benefit of less oil waste.
Improved fuel economy in certain engine configurations.
Better lubrication on cold starts
Longer engine life
The disadvantages of synthetic motor oils include
The lower friction may make them unsuitable for break-in (i.e. the initial run-in period of the vehicle) where friction is desirable to cause wear. Improved engine part machining has made break-in less critical than it once was, though. Many modern cars now come with synthetic oil as a factory fill.
Potential decomposition problems in certain chemical environments (industrial use dominantly)
Potential stress cracking of plastic components like POM (polyoxymethylene) in the presence of PAOs (polyalphaolefins).
Synthetics do not hold lead in suspension as well as mineral oil, thus caution is advised when the engine is run on leaded fuel. As an example, leaded fuel is still commonly used in aviation (avgas).
In July 1996, Consumer Reports published the results of a two year motor oil test involving a fleet of 75 New York taxi cabs and found no noticeable advantage of synthetic oil over regular mineral oil. In their article, they noted that "Big-city cabs don't see many cold start-ups or long periods of high speed driving in extreme heat. But our test results relate to the most common type of severe service stop-and-go city driving." According to their study, synthetic oil is "worth considering for extreme driving conditions: high ambient temperatures and high engine load, or very cold temperatures."
this is in the gold container, they also have semi synthetic for the same price
Synthetic oils are not recommended in automotive rotary engines.[