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Part synthetic oil can contain ANY proportion of synthetic to mineral oil - cans rarely, if ever, specify the proportion.
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The thread posted by the webmaster at the top of the list, entitled 'oil specification and viscosity information' deals with this subject in detail.
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The thread posted by the webmaster ... deals with this subject in detail.
This does not cover oil types, for which you need Oilman's other excellent post:
www.honestjohn.co.uk/forum/post/index.htm?v=e&t=32...1
To quote:
"Indeed, cheapening tricks. Magnatec is a mineral oil with a very small percentage of ester added to give it polarity. I've seen chemical analysis!
So, what is a synthetic?
Well up until the Mobil vs Castrol [legal] case it was simple, it was and still is in my book "manmade" and built in laboratories by chemists. It still is and made of poly alpha olefin and/or ester.
However (shame on the judge), it no longer means this as Castrol won the right to call highly modified mineral oils (hydrocracked) synthetic and so the flood gates where opened!
Now oil manufacturers are able to call a smart looking can of cheap mineral oil with a small % of hydrocracked oil in it a synthetic, shameful but legal.
Real synthetics are out there but due to the costs of producing them not always the best option (bottom line) for oil manufacturers when they are compared with the profits made from mineral oils labelled as synthetics.
Basestocks used are the key and group IV / V are proper synthetics the rest are petroleum based.
Here are the basestock catagories which are clear but discovering what's in a tin requires chemical analysis as the word "synthetic" is now meaningless unless qualified.
Ignore the marketing hype and sales literature as it's generally misleading and look at the technical data on the oil, this will give you a good idea what's in the can!
Basestock categories and descriptions
All oils are comprised of basestocks and additives. Basestocks make up the majority of the finished product and represent between 75-95%.
Not all basestocks are derived from petroleum, in fact the better quality ones are synthetics made in laboratories by chemists specifically designed for the application for which they are intended.
Basestocks are classified in 5 Groups as follows:
Group I
These are derived from petroleum and are the least refined. These are used in a small amount of automotive oils where the applications are not demanding.
Group II
These are derived from petroleum and are mainly used in mineral automotive oils. Their performance is acceptable with regards to wear, thermal stability and oxidation stability but not so good at lower temperatures.
Group III
These are derived from petroleum but are the most refined of the mineral oil basestocks. They are not chemically engineered like synthetics but offer the highest level of performance of all the petroleum basestocks. They are also known as ?hydrocracked? or ?molecularly modified? basestocks.
They are usually labelled/marketed as synthetic or semi-synthetic oils and make up a very high percentage of the oils retailed today.
Group IV
These are polyalphaolefins known as PAO and are chemically manufactured rather than being dug out of the ground. These basestocks have excellent stability in both hot and cold temperatures and give superior protection due to their uniform molecules.
Group V
These special basestocks are also chemically engineered but are not PAO.
The main types used in automotive oils are diesters and polyolesters. Like the group IV basestocks they have uniform molecules and give superior performance and protection over petroleum basestocks. These special stocks are used in all aviation engines due to their stability and durability. Esters are also polar (electro statically attracted to metal surfaces) which has great benefits. They are usually blended with Group IV stocks rather than being used exclusively.
It is common practice for oil companies to blend different basestocks to achieve a certain specification, performance or cost. The blending of group IV and V produces lubricants with the best overall performance which cannot be matched by any of the petroleum basestock groups.
I sell oils and this frustrates the hell out of me because in the main, the buyer is not getting what he's paying for!"
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Mike Farrow
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Does that mean if the container is labelled "Fully Synthetic" that it is one of the last two groups, IV & V.
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>>> Does that mean if the container is labelled "Fully Synthetic" that it is one of the last two groups, IV & V.
No, it's group III.
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So how do I know if I'm buying a proper synthetic, i.e. one of group IV or V ?
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Even the "fully synth" contains 20% group II oil, to suspend the additives, which in turn make up around 20% of the total. The Group III oils are not uniform SFAIK: there are more rigorous processing than hydrocracking. The differences between Gp III and IV are not that great. However, I use Fuchs or similar quality synth (subject to the dilution as above!) on the basis that I don't want to change the oil unecessarily, but still keep it from cooking-up into sludge.
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So how do I know if I'm buying a proper synthetic, i.e. one of group IV or V ? <<
You'd be buying it from a specialist supplier, like Opie, and paying a lot of money - DON'T expect to pick up 5 litres of Group IV/V for £20 in your supermarket!
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I don't buy oil from supermarkets anyway and I don't have a local "specialist supplier", so how else would I know. What I'm trying to say is, if I went into a motor factors or a main dealer spares dept and saw two different brands of oil that were labelled "Fully Synthetic" one at say £30 and another at £50 for 5 litres, are they any different. Are they both hydrocracked minerals or are they PAO based, does the price tell me or is it a con.
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I use Mobil 1 0W-40, £28 / 4 litre. It's "fully synthetic" but only Group III, as far as I know. Other than mail order / online I've no idea whether anyone actually stocks PAO oils for retail sale.
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Mobil1 is PAO, surely?
yes, afaik.
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Mobil 1 switches to group III base oils :( ..
ashok:
all that i can find on that forum link is accusations/allegations that mobil-1 was switiching to group iii base oils.
no conclusive evidence on there that i can see, nor any link to the source of the unsubstantiated rumour, nor any mobil statement confirming the allegation.
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Hmm, Mobil themselves are pretty evasive though (though I accept it is American source)...
Question:
Response to Claims that Products Contain 'Mostly Mineral Oil'
I've seen claims of gas chromatograph analysis of Mobil 1 dated 10-06 that state it is "mostly mineral oil". Realizing that you cannot divulge your exact formulations, what do you say to the critics that claim you are using a high percentage of hydro processed mineral oil in Mobil 1 instead of the more expensive PAO or polyester base stocks?
Answer:
Just like other companies, we do not discuss our product formulations for obvious proprietary reasons. Mobil 1 is formulated using a combination of high performance fluids including PAO, along with a proprietary system of performance additives. But in the end, it is also about performance. Mobil 1 is used by more Original Equipment Manufacturers than any other oil as factory fill in their vehicles. Also take note of the kind of testing we put our product through, including the Las Vegas field testing we recently completed. The Mobil 1 technology is also tested each weekend on the race track. In fact, more than 50 percent of all NASCAR teams use Mobil 1.
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Hmm Mobil themselves are pretty evasive though
slippery by name slippery by nature!!!!
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Why are people so obssesive about engine oil? These days there are very few engine failures due to lubrication problems - when problems do arise its nearly always due to failure to change the oil, rather than a failure of the oil itself. Personally I would rather buy a slightly lower cost oil and change it more often.
Just buy an oil than meets your vehicle maker's specs and you'll be fine - and use an OE filter. Unless you are driving on a track there is no advantage to be gained in using the very expensive oils. Strangely no one seems to worry too much about transmission oil, even though there seem to be more lubrication-related problems with transmissions these days...
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Why are people so obssesive about engine oil?
Who knows Aprilia. I use the cheapest semi-synth oil ('Carlube' last time) and the cheapest filters (usually Fram), change every 4-5k. Engine is extremely quiet and timing chain is glad of nice fresh oil. All these "performance" oils are made for cost-cutting in servicing schedules - I would NEVER allow an engine to do 20k on the same oil, even if it was "made" for that sort of negligent servicing.
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I think there's an element of psychology here. People who service their cars generally "love" them and treat them as they would a child. Only their perception of what is the best will do.
In reality, Aprilia is right - in most cases. For a run of the mill engine, the cheapest oil to spec will do (that's what specifications are for) - lubrication failure these days is very rare as is severe engine wear unless abuse is evident. I would also agree with his sentiments concerning OE filters. Having sectioned a fair number of these, there are some very poor examples on the market, mainly either of American origin or Far Eastern fakes.
Most engine oil is changed more frequently than is necessary - technology has moved on. Commercial engines run to very many more miles per change than passenger car engines generally do. There is nothing wrong with a 20k mile oil change interval if the right oil, filter, fuel and operating regimen is adhered to.
659.
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I think there's an element of psychology here. People who service their cars generally "love" them and treat them as they would a child.
LOL! Too true - in fact I think a lot of people think more of their cars than their children...
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I think there's an element of psychology here. People who service their cars generally "love" them and treat them as they would a child.
I DIY-service, purely becuase it's the cheapest way of running a car! I change oil/filter every 6 months regardless of mileage because I want the engine to go on forever. Certainly wouldn't waste money on brand-named oil that conforms to the same spec as cheap oil. But, each to their own.
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Texaco Havoline 5w40 Fully synthetic is PAO based, I emailed texaco and asked
£13.99 for 5 Litres at JTF warehouse
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my cars last oil change had semi synth put in , when i come to do the next oil change in a couple of months can i use fully synth or aint it worth bothering about?
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Not worth bothering about at all. Chances are it'll only require a SJ (or older) spec - you'll have a hard job finding a semi-synth oil on the market now that doesn't meet the later and better SL spec. Spending more on fully synth would be foolish. My car's overdue an oil-change, and it'll get Tesco's own brand semi-synth, just as it's been running on since soon after I bought it.
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Chances the oil longevity and effectiveness depends on the OEM spec, which is less often API and more often ACEA. Or specific to the maker. VW, Ford, GM, Mercedes all specify oils which are formulated for the relevant engine. Failures are known, especially thousands of Toyota Mercedes and VW engines in the States, where low grade API oils were used by unwitting garages resulting in thousands of engine failures due to sludge. Best bet is to follow the OEM guidance, IMHO.
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Chances the oil longevity and effectiveness depends on the OEM spec which is less often API and more often ACEA.
API is a US-based spec and used by Japanese and US-based (inc. Ford and GM) makers, and also quoted by some European makers. ACEA is the European equivalent - so if you have a Renault you'll see an ACEA spec quoted, rather than API.
Failures are known especially thousands of Toyota Mercedes and VW engines in the States where low grade API oils were used by unwitting garages resulting in thousands of engine failures due to sludge.
Not really relevant to Europe. US-spec engines are usually designed to run on lower Octane fuel and have higher levels of EGR etc. to meet more stringent emissions specs. There we 'sludging' problems in Europe quite a few years back, but in recent times I have never heard of engine sludging other then where an engine has overheated or has not had the oil changed in a long time (or been in storage). In a modern engine, using modern oils, the amount of wear is tiny, and hard to discern even on 100K+ mile engines. Very very few cars are 'killed' these days by a worn out engine.
>>Best bet isto follow the OEM guidance IMHO.
That's true, but if the car is more than a couple of years old you'll probably find that the oils in you local factor beat the OEM spec. For example API 'SM' is now becoming mainstream.
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SFAIK, the octane of the fuel in USA is about the same, although the numbers at the pump seem lower, so I can't see that was an issue. RON (UK) and MON/PON (US and others) are slightly different. 95 RON is equivalent to 87 MON and 91 PON. www.btinternet.com/~madmole/Reference/RONMONPON.ht...l The car industry in the US was less used to high oil stress engines, so used oils that the trade were used to in larger engines, ignoring the fact that most oil available was Gp II. However, sludge is not unknown over here, and some Saab engines running semi-synth have apparently been afflicted, and reminder given by SAAB to use fully synth. tinyurl.com/22go55
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I get more miles per gallon with proper synthetic oil than with normal oil.
I save the extra cost of the synthetic oil by the mileage at which I would have changed the non synthetic oil.
The synthetic oil, judged by annular planar chromatography tests, lasts more than twice as long as non synthetic oil.
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annular planar chromatography tests.
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AKA, Blotter test, spot check etc.
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SFAIK the octane of the fuel in USA is about the same although the numbers at the pump seem lower so I can't see that was an issue. RON (UK) and MON/PON (US and others) are slightly different. 95 RON is equivalent to 87 MON and 91 PON
I have spent the best part of lifetime working in the motor industry, including jobs involving the adaption of European engines for the US market. In general it is assumed that the engine must run on 91RON equivalent (US 87PON). Also the US emission regs require higher levels of EGR and slightly different crankcase venting.
Like I said, never seen a sludged engine in the UK in recent years. It just will not happen using API SL spec. or better, assuming not over overheating etc. Engine lubrication is now probably one of the things you have to worry least about.
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The small octane difference: how does that contribute to sludging? It still seems to me that it is a function of the lubricant, and possibly fuel quality.
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