Andrew Timmins

A subject which was mentioned in your lubricating a Subaru thread was the sale of hydrocracked mineral oil as synthetic. If I pay for a synthetic oil I want to receive a synthetic oil, not a cheap tarted up mineral oil sold at a vast profit.

With this in mind, do you know what synthetic base stocks are used in some of the more popular and easy to find oils? Are they hydrocracked(group III), PAO(group IV) or ester(group V)?

They oils I would like to know about are:

Mobil 1
Motul
Silkolene
Castrol RS
Millers
Comma - part of Exxon Mobil
Shell
Carplan Triple R

If you have information on these and other synthetic oils I would be grateful.

Regards

Andrew

oilman

iTrader: (9)

Andrew,

Not sure on all of them but can answer as follows:

Mobil 1 = PAO
Motul = Not all are proper but believe V300 is Ester
Silkolene = All Pro S and R are Ester
Castrol RS = 10w-60 Hydrocracked (SLX 0w-30 PAO)
Millers = Hydrocracked as far as I'm aware
Comma - part of Exxon Mobil = AVOID definately hydrocracked
Shell = Most are hydrocracked, there are some PAO's
Carplan Triple R = Hydrocracked
Fuchs Supersyn SL range = PAO
Total = Some PAO, most hydrocracked
Valvoline = Hydrocracked
Redline = Most Ester
Royal Purple = Most Ester


Hope this helps,
Simon

oilman

iTrader: (9)

Oh forgot to mention that all 0w oils will need to be PAO to meet 0w and 5w oils will need to be at least a PAO blend to meet 5w.

Above this, 10w, 15w and 20w etc, you need to know what you are buying!

Cheers
Simon

Andrew Timmins

Thank you very much for that Simon.

I'm quite suprised that Comma is hydrocracked, if I'd been a betting man I would have put money on it being PAO, what with them being part of Mobil now.

Looks like all of the cheaper synthetic brands are hydrocracked. Oh well, at least I now know which brands to avoid and those who supply a real synthetic oil.

JohnD

iTrader: (5)

Oilman
A number of the makes you state as being hydrocracked produce 0w and 5w synthetics, but you state that these would need to be PAO to meet that end of the grade. E.G. I am currently using Millers XFS5w/40 (having great difficulty in obtaining the 5w/50 version) so I am wondering where this oil sits in the great scheme of things?
JohnD

oilman

iTrader: (9)

I believe that a small number of Millers oils contain some ester but you'd need to check as their website doesn't mention anything.

5w-50 is a difficult grade to get hold of as most companies recommend the more readily available 5w-40 which most OEM's today specify alongside 0w oils.

Oils in general are moving thinner due to fuel economy, power delivery and emmissions (0w or 5w) the likes of VW/Audi, BMW, Porsche, Honda, Ford, GM, and many others now specify these thinner oils.

I have loads of different grades but only 1 5w-50 which is a PAO.

It's a changing market and the OEM's are driving it.

Cheers
Simon

WRX STI Type RA.

Interesting reading....But what the hells PAO....Please.....?.

Jiggerypokery

Poly Alpha Olefin.

oilman

iTrader: (9)

Thanks for that, here's further explanation:

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 more than 150, and they have extremely low pour points (normally below –20 degrees C). 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 -30 to -40 degrees C) 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 -45 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. You get what you pay for!

Cheers
Simon