Thought this interesting article by a leading R&D Chemist would open some eyes.
A word of caution ? You get what you pay for!
Below is an article written by John Rowland, Silkolene/Fuchs Chief R & D Chemist for 40 years.
Quote:
Costs of synthetics vary considerably. The most expensive are the ?Ester? types originally only used in jet engines. These cost 6 to 10 times more than high quality mineral oils.
The cheapest synthetics are not really synthetic at all, from a chemists point of view. These are in fact specially refined light viscosity mineral oils known as ?hydrocracked?. These have some advantages over equivalent mineral oils, particularly in lower viscosity motor oils such as 5w-30 or other oils with a low ?W? rating such as 5w-50 etc and they cost about 1.5 times more than good quality mineral fractions.
We use several different grades of this base oil, where appropriate. This is the ?synthetic? which is always used in cheap oils that are labelled ?synthetic?. Yes it?s a cruel world, you get what you pay for!
Now, you may ask, why are these special mineral oils called ?synthetic??
Well, it was all sorted in a legal battle that took place in the USA about ten years ago. Sound reasons (including evidence from a Nobel Prize winning chemist) were disregarded and the final ruling was that certain mineral bases that had undergone extra chemical treatments could be called ?synthetic?.
Needless to say, the marketing executives wet their knickers with pure delight! They realised that this meant, and still does, that the critical buzz-word ?synthetic? could be printed on a can of cheap oil provided that the contents included a few percent of ?hydrocracked? mineral oil, at a cost of quite literally a few pence.
So, the chemistry of ?synthetics? is complex and so is the politics!
The economics are very simple. If you like the look of a smart well-marketed can with ?synthetic? printed on it, fair enough, it will not cost you a lot; and now you know why this is the case.
But, if you drive a high performance car, and you intend to keep it for several years, and maybe do the odd ?track day?, then you need a genuine Ester/PAO (Poly Alpha Olefin) synthetic oil.
This oil costs more money to buy, because it costs us a lot of money to make, very simply, you always get what you pay for!
Unquote:
This is old news really but most people are blissfully unaware of the facts when they are looking for a "synthetic" oil which although labelled as such and is more expensive probably is not a true synthetic basestock. Always remember proper synthetics are not cheap so don't be fooled.
Cheers
Simon
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Note in particular that Castrol Magnatec is not a semi-synthetic oil but a mineral oil disguised by Castrol's misleading weasel words "synthetic engineering" on the can. It's a perfectly good mineral oil though.
I assume Mobil 1 is a genuine synthetic.
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Correct, it's a hydrocracked mineral oil with a smart can and good marketing.
Mobil 1 is a proper Group 4 basestock (poly alpha olefin).
This is basically what basestocks are all about:
?HYDROCRACKED? (HC) or MOLECULARLY CONVERTED (MC) BASESTOCKS
There are many petroleum oils available on the market that are so pure and refined, they can now be passed off as synthetics.
They are not made from true synthetic basestocks (at least not in the way that synthetics have traditionally been defined), but they have so little in common with traditional petroleum basestocks, it is really somewhat silly to classify them as petroleum oils.
Petroleum oil basestocks can be put through a super-extreme refining process called ?hydrocracking?. In some cases, as in the case of one particular name-brand "synthetic" oil, these highly refined petroleum basestocks can actually be termed and sold as "synthetic".
It is completely legal for lubricants manufacturers to label these oils as "synthetic".
These are extremely high performance petroleum basestocks, but they are not truly synthetic the way that most people understand the term and will not necessarily perform to the same level as a premium synthetic oil like PAO (poly alfa olefins) or Esters.
Hydrocracking involves changing the actual structure of many of the oil basestock molecules by breaking and fragmenting different molecular structures into far more stable ones. This results in a basestock which has far better thermal and oxidative stability as well as a better ability to maintain proper viscosity through a wide temperature range - when compared to a typical petroleum basestock.
Although contaminants are still present, and these are still petroleum basestocks, contamination is minimal and performance characteristics are high. This process also can turn a wider range of crude oil stock into well-performing petroleum lubricant basestocks.
TYPES OF SYNTHETIC BASESTOCKS
Synthetic basestocks are not all the same. There are few different chemical types that may be used as synthetic basestock fluids. There are only three that are seen commonly in automotive applications:
Polyalphaolefins (PAO's)
These are the most common synthetic basestocks used in the US and in Europe. In fact, many synthetics on the market use PAO basestocks exclusively. PAO's are also called synthesized hydrocarbons and contain absolutely no wax, metals, sulfur or phosphorous. Viscosity indexes for nearly all PAO's are around 150, and they have extremely low pour points (normally below ?40 degrees F).
Although PAO's are also very thermally stable, there are a couple of drawbacks to using PAO basestocks. One drawback to using PAO's is that they are not as oxidatively stable as other synthetics. But, when properly additized, oxidative stability can be achieved.
Diesters
These synthetic basestocks offer many of the same benefits of PAO's but are more varied in structure. Therefore, their performance characteristics vary more than PAO's do. Nevertheless, if chosen carefully, diesters generally provide better pour points than PAO's (about -60 to -80 degrees F) and are a little more oxidatively stable when properly additized.
Diesters also have very good inherent solvency characteristics which means that not only do they burn cleanly, they also clean out deposits left behind by other lubricants - even without the aid of detergency additives.
They do have one extra benefit though, they are surface-active (electrostatically attracted to metal surfaces), PAO?s are not ?polar?, they are ?inert?.
Polyolesters
Similar to diesters, but slightly more complex. Greater range of pour points and viscosity indexes than diesters, but some polyolester basestocks will outperform diesters with pour points as low as -90 degrees F and viscosity indexes as high as 160 (without VI additive improvers). They are also ?polar?.
Other synthetic basestocks exist but are not nearly as widely used as those above - especially in automotive type applications. Most synthetics on the market will use a single PAO basestock combined with an adequate additive package to provide a medium quality synthetic lubricant. However, PAO basestocks are not all the same. Their final lubricating characteristics depend on the chemical reactions used to create them.
Premium quality synthetics will blend more than one "species" of PAO and/or will blend these PAO basestocks with a certain amount of diester or polyolester in order to create a basestock which combines all of the relative benefits of these different basestocks.
This requires a great deal of experience and expertise. As a result, such basestock blending is rare within the synthetic lubricants industry and only done by very experienced companies. In addition, although such blending creates extremely high quality synthetic oils, they don't come cheap.
Cheers
Simon
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Oilman,
This was very good & interesting reading. The only thing missing from a novice piont of view is - what should we go out & buy?
I need 5w30 for a Zetec but would not know where to start or who to buy from without getting ripped off.
Perhaps you could give us all a few tips
Any help really would be appreciated
Thanks
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Interesting stuff. Is there any way of knowing by looking at the container, or is there a list anywhere, of what is the 'real stuff.'
I have used French Hypermarkets own brand synthetics for years with great effect. I presume it may not be the real stuff, but maybe....
Any way of telling?
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Davee: for a Ford
Shell Helix fully synthetic.. Our local Ford dealer stocks it..
or Mobil 1
madf
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have you got a price on that?
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I wish it was simple but as explained above by the Chemist, the labelling issue has created a veritable minefield so the only thing that I can offer is some rough guidance.
0w oils will be synthetic as they need the proper stuff (pao/ester) to meet API pour and flashpoints etc.
5w oils need a percentage of the good stuff to meet the guidelines as mentioned above but there is a big difference between the percentages and care should be taken.
10w, 15w, 20w oils are in the main either "hydrocracked" or mineral oils but they are generally petroleum based oils and not synthetics although there are a few notable exceptions, see below.
All semi-synthetics are "hydrocracked" oils and not synthetics.
Oils with labels which say, synthetic blend, part-synthetic, semi-synthetic etc are once again "hydrocracked" oils.
On the basis that true synthetics (poa/esters) are expensive because they are made in laboratories, price is always a good indicator of quality (although some major brands attract a premium) so anything under £7.00 per litre is not going to be a proper synthetic. It may contain a small percentage of the good stuff to make the technical data look better but will not be a 100% true synthetic oil. "Bargain oils" are always modified mineral oils and in some cases afford less protection than minerals.
Although manufacturers use different synthetics, pao's (poly alpha olefins) are the most commonly used. Esters which are considered to be the best by the purists (especially blended with pao) are expensive and only used by specialist companies why blend high quality "race and competition oils".
I my opinion, the best oils are poa/ester blends (80% pao / 20% ester) as these cleverly use the benefits of the different synthetic basestocks.
Esters
All jet engines are lubricated with synthetic esters, and have been for 50 years, but these expensive fluids only started to appear in petrol engine oils about 20 years ago.
Thanks to their aviation origins, the types suitable for lubricants (esters also appear in perfumes; they are different!) work well from ?50 degC to 200 degC, and they have a useful extra trick.
Due to their structure, ester molecules are ?polar?; they stick to metal surfaces using electrostatic forces. This means that a protective layer is there at all times, even during that crucial start-up period. This helps to protect cams, gears, piston rings and valve train components, where lubrication is ?boundary? rather than ?hydrodynamic?, i.e. a very thin non-pressure fed film has to hold the surface apart. Even crank bearings benefit at starts, stops or when extreme shock loads upset the ?hydrodynamic? film.
The following oils are proper synthetics and their price also reflects this. This list is not exhaustive but at least gives buyers a place to start looking.
Silkolene PRO S (ester/pao)
Silkolene PRO R (ester/pao)
Motul 300V (ester/pao)
Motul 8100 (ester/pao or pao)
Mobil1 (pao)
Shell Helix ULTRA (pao)
Castrol RS Power (pao)
Fuchs Supersyn SL (pao)
Redline (ester/pao)
Amsoil (ester/pao)
Basestocks have a group number that identifies the type. ONLY group IV or V are proper synthetics. IV is PAO, and V is other synthetics including esters.
Just bear in mind that "you get what you pay for" is always a good starting point, oil companies are some of the best marketeers in the world so it's a case of buyer beware!
Hope this helps,
Cheers and seasons greetings,
Simon
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Use Ford /Texaco 5w/30 in your Ford, change it every 6000 miles and you wont go wrong. I personally would not spend my money on synthetic. My feeling is, and I may be wrong, that the reason we have to change oil so frequently is because the oil becomes contaminated. Unless you revise and enhance the filtration to a much smaller medium a synthetic oil, true or otherwise will become just as contaminated in the same amount of time. I used to use Amsoil full synthetic in my old Mitsubishi Van because of the mileages I used to rack up mostly short stop-start. In addition to the original filter I had a HUGE by-pass filter plumbed in which kept the oil extremely clean and only needed replacement every 25k miles. I think it may have contained Fullers Earth.
Andrew
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Simplicate and add lightness!!
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Oilman,
I am hugely impressed by your posts in this thread. I have recently bought an Alfa 156 (who's that laughing at the back?) and, of course, Alfa recommend their own Selenia 20k 10w-40. I thought this was a genuine fully synthetic oil, but it is not on your list of genuine synthetic oils. Is it, as I now suspect, a 'faux' synthetic, little different from Shell helix Plus or Castrol Magnatec 'synthetic engineering'?
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I've used a "semi-synthetic" at around £15 per 5L, changed at 5-6K together with oil filter, and the old MK2 Golf has gone to 185K with no discernable wear! The inside of the rocker cover and tappets are like new, absolutely sludge free! Do you need any more than that for normal motoring?
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If I ever get to buy a Skyline GT-R with twin-turbo's and 400BHP then I'll probably also invest in some 'proper synthetic' oil for it. For my current cars (which spend most of their time tootling in traffic) I generally use the Halford 5W-40 'fully synthetic' which is "on offer" about 6 times a year at £14.99 for 5l (its on offer at the moment, BTW).
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Oilman good to see this article repeated, I've come across it before. Opinions on synth, semi-synth or plain good old dino oil are like the proverbial: everybody has one (gotta watch that "offensive" tab now !!). You should see how some of threads on this in other forums (fora?) go on for ever about this with no conclusive result.
On the one hand I have read of US truckers with Cummins diesels running 100,000 miles on synth with only filter changes and whose engines stil have the honing marlks on the bore when they pull them down, and on the other, otherwise good engines leaking all over the place after a change to synth. Who to believe. The marketing pimples or the grizzled old wrenchers?
For me choice of oil (in my bikes and cars), subject to suitable grade of course, is a lot less important than (1) regular changes and new filters and (2) what the manual says. I distrust fully synth in the bikes because I still hear stories of roller bearing "skate", so I stick with m/cycle dino blends. In the cars semi-synth seems fine and anyway I'll have sold them on long before their engines will have worn out.
Just my $0.02.
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Interesting to note that the permitted use of the description synthetic was varied as a result of a court case. However I assume (it does not appear to be stated) that this took place in the USA. Is the same ruling valid in the UK (or Europe?).
If not binding in the UK, does this mean some manufacturers are making false claims based on the USA ruling? Some bored Trading Standards employee could make a name for himself here! or cost his local authority a lot of money in legal fees.
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pmh (was peter)
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