Oil recommendations

[TopBear]

Looking to do an oil change on the car soon, and had the last one done at MRC. (Not sure what they use??)

Shortlist is down to :-

Castrol Edge 10W-60......(Supercedes Castrol RS )
Mobil-1 0W-40......(It represents good value costing <£30\4litres @ Costco)
Motul 8100 0W-40......(Oilmans recommendation)

Any opinions on the above?

[Doug_S2]

VW synta gold on non tracked or abused cars and even in winter on tracked cars.

castrol 10w60 for cars driven hard.

[bigandyw]

Hows Silkolene pro S 10w 50?

i started using this after Oilmans recommendation in my Escort cosworth and it was always nice and quite even when very hot and used very little between changes, definatly my first choice of oil from now on!

[davs4]

Hows Silkolene pro S 10w 50?

i started using this after Oilmans recommendation in my Escort cosworth and it was always nice and quite even when very hot and used very little between changes, definatly my first choice of oil from now on!

I gave Oilman my engine spec and he too quoted Silkolene pro S 10w 50.
I run Castrol 10w 60 at the moment, is the swap worthwhile?

[Virdee Autos]

Isn't the 10W60 a bit too thick?

What is recommended in the manual by Audi weight-wise?

[bigandyw]

I've cut and pasted this from a post on Passionford, there are many more if u want them swapping over..

I'm posting this as it's of general interest to all here.

What's more, it's fact not fiction so please take time to read it.

Due to the court case in the states between Mobil and Castrol, you may not always be getting what you think you are so be careful, hydrocracked oils are not synthetics in the true sense of the word as they are molecularly converted petroleum oils, synthetics are not, they are built by chemists in laboratories "brick by brick" and are far superior.

Unfortunately, apart from in Germany, a manufacturer can label the inferior "hydrocracked" oils as synthetics and therefore the only true way of working out the quality is price although even this is not certain as there are some very expensive "hydrocracked" oils out there which are sold on their brand name, Castrol is a good example as they were the Company that Mobil took to court over the labelling issues.

Here is some more reading for those interested:

“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. You get what you pay for!

The castrol is Hydrocracked and the silkolene is a true synthetic thats why he recommends it

[Virdee Autos]

Does anyone know if the Synta Gold from VW is hydrocracked or a proper synthetic?

[bigandyw]

heres another good one from Oilman...
It's a question I get asked all the time so I thought that I'd clear up one of the most common misconceptions about oil viscosity.

"What's the difference between a 10w-40 and a 5w-40?"

I read the following comments all the time!

"You must not use 5w oils"

"5w oils are too thin"

"10w-40 is ok but don't use 5w-40!"

Some facts need to be straightened out here and hopefully I can do this without losing those that are interested.

So what is the difference between a 5w-40 and a 10w-40 @100degC?

NONE!

SAE determines the viscosity (+/-) that the oil needs to be at 100 degC and these need to be met in tests to give the oil it's API rating (xw-xx or xxw-xx).

They are as follows: (within a margin)

SAE 30 = 11.00cst
SAE 40 = 14.00cst
SAE 50 = 18.50cst
SAE 60 = 24.00cst

Compare these SAE 40 oils at 100degC (0w, 5w, 10w, 15w)

Motul 300V 5w-40.................Viscosity = 13.80cst
Motul 300V 10w-40................Viscosity = 14.00cst
Silkolene PRO S 5w-40............Viscosity = 14.89cst
Motul 8100 X-cess 5w-40........Viscosity = 14.00cst
Fuchs Titan Supersyn 5w-40....Viscosity = 13.60cst
Castrol Performance 10w-40.....Viscosity = 14.50cst
Silkolene XTR 10w-40 (semi).....Viscosity = 14.70cst
Mobil 1 0w-40........................Viscosity = 14.30cst
Motul 8100 0w-40...................Viscosity = 13.30cst
Silkolene Turbolene D 15w-40....Viscosity = 14.40cst
Total Quartz 15w-40...............Viscosity = 14.50cst

These figures are not by chance and include synthetics, semi-synthetics and mineral oils they are all in the range to be labelled a Xw or XXw-40 multigrade oil.

So, what's the "W" number all about then?

It stands for "winter" not "weight" as often confused and called on many U.S. articles on oil!

This number is the "cold crank" viscosity and nothing to do with the oil viscosity when the engine is up to temperture. These numbers are related to the oils ability to operate in cold temperatures. 0w oils were originally designed to operate in arctic climates that's why they operate at ferrous monkey endangering temperatures of -35degC and below!

The benefits of the lower viscosity oils (0w and 5w) is that they flow more easily and quickly when cold and therefore protect the engine better on cold start when 80% of the engine wear occurs.

So, yes it's true an sae 40 is an sae 40 when hot whether its a 0w, 5w, 10w, 15w or whatever and that's a fact. The same goes for 20's, 30's, 50's, 60's and so on.

Hope this helps.

Cheers

[bigandyw]

Does anyone know if the Synta Gold from VW is hydrocracked or a proper synthetic?

I'll keep flicking through his posts see what i can find?

[bigandyw]

This is a good Post oilman made about "synthetic's" No mention of your synta gold tho, he might well see this post and Add to it!

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 article is something that all car owners should read and understand before buying oil and I’ve posted this with Johns permission.

Cheers

[TopBear]

Found a related post on another forum which Simon (Oilman) has categorised the oils he knows in the respective category........

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

[Turbo Joe]

We need you Oilman on this one.

[JonnyX]

I have Silkolene Pro 10-50w. It's in my garage. I can't say how good it is but
it looks yummy. It should hopefully be going in with my K04's 15-22nd Dec.

[A20LEE]

Any opinions on Shell Helix Ultra 5w/40? Seems to be the most easily available 5w/40 if i ever need a top up. My car is a standard RS4 with 85k miles doing about 6k a year and the oil willbe changed every 6 months.

[RS4_Schumi]

Recommend the Silkolene too.... and they'll usually do you a good deal on it if you call them up.
http://www.opieoils.co.uk/