Basestock categories and descriptions
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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.

Cheers

Guy

Is this SPAM?

no it's not spam, i just thought i would post these oil threads as they might be intersting to some people.

I think it is sx_turbo1 copying stuff from somewhere else. Illegal.

Most of it irrelevant if you have a gearbox sitting under the engine.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

no it's not irrevelent if you have a gearbox sitting under the engine.

the same principles still applies, you can still buy decent oils,

i just thought people might find it interesting,

and why is it illegal to copy stuff than has been publicly posted on another forum?

Someone called "Oilman" spamming several other forums comes to mind...

And, as Paul says, mostly irrelevant for the Mini engine/gearbox configuration.

Schrödinger's cat - so which one am I ???

it's still not irrelivant,

and yes they are by oil man, but they arent spam,

what are peoples reasoning for it not being relevent on a mini just because your engines use the same oil for the gearbox, in technical terms please,

a healthy discussion would be nice rather than "your wrong", or "it's spam"

Did it really need 5 threads?

In the 13's at last!.. Just

also bear in mind that the originally recomended oil for a mini was 10w40, and all my books at work (comma, valvoline, castrol etc etc) all recomend to put 10w40 semi-synthetic in a mini and metro in the 80's/90's

so why cant you put anything else in it other than mineral oils?

Edited by sx_turbo1 on 7th Jul, 2009.

Over the years, this subject has been discussed time and time again on TM.

Essentially, it always boils down to the fact that there are very few oils suited to our specific needs.

I only know of one, Millers CVT, that has been proven to do the business on a highly stressed turbocharged Mini engine and gearbox.

Millers CVT is a semi-synthetic, but has the correct additives.

If someone can come up with a specific oil that works as well as CVT and save us a few quid, then I'm interested. Otherwise it's a re-run of the same old thing.

To post up text by someone else without crediting the original author may be illegal. If it's not then it should be. Besides I've seen this before on TM somewhere.

EDIT: One of the best threads on TM about oil:

Edited by Paul S on 7th Jul, 2009.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

someone ban this cunt quick

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"