oil explained

[mapblue]

Saw this and found it quite a good read.

 
What’s written on your oil bottle and what does it mean.

This post may seem like going back to basics but I am constantly surprised by the amount of people who do not know or understand what is written on a bottle of oil and therefore no idea of what they are buying/using.

To be blunt about the subject, if a bottle of oil does not contain the following basic information then DO NOT buy it look for something that does!

1) The purpose for which it is intended (i.e. Motor oil, Gear oil etc)

2) The viscosity (i.e. 10w-40, 5w-30 etc for Motor oils and 80w-90, 75w-90 etc for Gear oils)

3) The specifications that it meets (should contain both API and ACEA ratings)

4) The OEM Approvals that it carries and the codes (i.e. MB229.3, VW503.00, BMW LL01 etc)

Ignore the marketing blurb on the label it is in many cases meaningless and I will explain later what statements you should treat this with some scepticism

So, what does the above information mean and why is it important?

THE BASICS

All oils are intended for an application and in general are not interchangeable. You would not for example put an Automatic Transmission Oil or a Gear Oil in your engine! It is important to know what the oils intended purpose is.

VISCOSITY

Most oils on the shelves today are “Multigrades”, which simply means that the oil falls into 2 viscosity grades (i.e. 10w-40 etc)

Multigrades were first developed some 50 years ago to avoid the old routine of using a thinner oil in winter and a thicker oil in summer.

In a 10w-40 for example the 10w bit (W = winter, not weight or watt or anything else for that matter) simply means that the oil must have a certain maximum viscosity/flow at low temperature. The lower the “W” number the better the oils cold temperature/cold start performance.

The 40 in a 10w-40 simply means that the oil must fall within certain viscosity limits at 100 degC. This is a fixed limit and all oils that end in 40 must achieve these limits. Once again the lower the number the thinner the oil, a 30 oil is thinner than a 40 oil at 100 degC etc. Your handbook will specify whether a 30, 40 or 50 etc is required.

SPECIFICATIONS

Specifications are important as these indicate the performance of the oil and whether they have met or passed the latest tests or whether the formulation is effectively obsolete or out of date.
There are two specifications that you should look for on any oil bottle and these are API (American Petroleum Institute) and ACEA (Association des Constructeurs Europeens d’Automobiles) all good oils should contain both of these and an understanding of what they mean is important.

API

This is the more basic as it is split (for passenger cars) into two catagories. S = Petrol and C = Diesel, most oils carry both petrol (S) and diesel (C) specifications.

The following table shows how up to date the specifications the oil are:

PETROL

SG - Introduced 1989 has much more active dispersant to combat black sludge.

SH - Introduced 1993 has same engine tests as SG, but includes phosphorus limit 0.12%, together with control of foam, volatility and shear stability.

SJ - Introduced 1996 has the same engine tests as SG/SH, but phosphorus limit 0.10% together with variation on volatility limits

SL - Introduced 2001, all new engine tests reflective of modern engine designs meeting current emissions standards

SM - Introduced November 2004, improved oxidation resistance, deposit protection and wear protection, also better low temperature performance over the life of the oil compared to previous categories.

Note:

All specifications prior to SL are now obsolete and although suitable for some older vehicles are more than 10 years old and do not provide the same level of performance or protection as the more up to date SL and SM specifications.

DIESEL

CD - Introduced 1955, international standard for turbo diesel engine oils for many years, uses single cylinder test engine only

CE - Introduced 1984, improved control of oil consumption, oil thickening, piston deposits and wear, uses additional multi cylinder test engines

CF4 - Introduced 1990, further improvements in control of oil consumption and piston deposits, uses low emission test engine

CF - Introduced 1994, modernised version of CD, reverts to single cylinder low emission test engine. Intended for certain indirect injection engines

CF2 - Introduced 1994, defines effective control of cylinder deposits and ring face scuffing, intended for 2 stroke diesel engines

CG4 - Introduced 1994, development of CF4 giving improved control of piston deposits, wear, oxidation stability and soot entrainment. Uses low sulphur diesel fuel in engine tests

CH4 - Introduced 1998, development of CG4, giving further improvements in control of soot related wear and piston deposits, uses more comprehensive engine test program to include low and high sulphur fuels

CI4 Introduced 2002, developed to meet 2004 emission standards, may be used where EGR ( exhaust gas recirculation ) systems are fitted and with fuel containing up to 0.5 % sulphur. May be used where API CD, CE, CF4, CG4 and CH4 oils are specified.

Note:

All specifications prior to CH4 are now obsolete and although suitable for some older vehicles are more than 10 years old and do not provide the same level of performance or protection as the more up to date CH4 & CI4 specifications.

If you want a better more up to date oil specification then look for SL, SM, CH4, CI4

ACEA

This is the European equivalent of API (US) and is more specific in what the performance of the oil actually is. A = Petrol, B = Diesel and C = Catalyst compatible or low SAPS (Sulphated Ash, Phosphorus and Sulphur).

Unlike API the ACEA specs are split into performance/application catagories as follows:

A1 Fuel economy petrol
A2 Standard performance level (now obsolete)
A3 High performance and/or extended drain
A4 Reserved for future use in certain direct injection engines
A5 Combines A1 fuel economy with A3 performance

B1 Fuel economy diesel
B2 Standard performance level (now obsolete)
B3 High performance and/or extended drain
B4 For direct injection car diesel engines
B5 Combines B1 fuel economy with B3/B4 performance

C1-04 Petrol and Light duty Diesel engines, based on A5/B5-04 low SAPS, two way catalyst compatible.
C2-04 Petrol and light duty Diesel engines, based on A5/B5-04 mid SAPS, two way catalyst compatible.
C3-04 Petrol and light duty Diesel engines, based on A5/B5-04 mid SAPS, two way catalyst compatible, Higher performance levels due to higher HTHS.

Note: SAPS = Sulphated Ash, Phosphorous and Sulphur.

Put simply, A3/B3, A5/B5 and C3 oils are the better quality, stay in grade performance oils.

APPROVALS

Many oils mention various OEM’s on the bottle, the most common in the UK being VW, MB or BMW but do not be misled into thinking that you are buying a top oil because of this.

Oil Companies send their oils to OEM’s for approval however some older specs are easily achieved and can be done so with the cheapest of mineral oils. Newer specifications are always more up to date and better quality/performance than the older ones.

Some of the older OEM specifications are listed here and depending on the performance level of your car are best ignored if you are looking for a quality high performance oil:

VW – 500.00, 501.00 and 505.00

Later specs like 503, 504, 506 and 507 are better performing more up to date oils

MB – 229.1

Later specs like 229.3 and 229.5 are better performing more up to date oils.

BMW – LL98

Later specs like LL01 and LL04 are better performing more up to date oils.


FINALLY

Above is the most accurate guidance I can give without going into too much depth however there is one final piece of advice regarding the labelling.

Certain statements are made that are meaningless and just marketing blurb, here are a few to avoid!

Recommended for use where……………
May be used where the following specifications apply……………
Approved by………………………..(but with no qualification)
Recommended/Approved by (some famous person, these endorsements are paid for)
Racing/Track formula (but with no supporting evidence)

Also be wary of statements like “synthetic blend” if you are looking for a fully synthetic oil as this will merely be a semi-synthetic.

Like everything in life, you get what you pay for and the cheaper the oil the cheaper the ingredients and lower the performance levels.

 

[Murph]

Good info fella!

I have made this a sticky so as many members as possible can benefit from it.

[stevem]

Always said,never scrimp on oil always buy the best you can afford.

[bstardchild]

Looks like an Oilman post to me........ They are always full of great info

Only a small point but might be better if you "quoted" the source on a public forum as some people can get a bit upset about having their "info" reposted without acknowledgement - if it was an Oilman post I'm sure he wouldn't mind but like I said people can get funny about stuff like this

[Johnraka]

Bloody hell! Good one!

I never knew there was so much behind it, to me oil was oil, will certainly be more choosy in future.

Thanks my man, much appreciated. 

[melinx]

An interesting report from a massive test which reckons that so long as the oil complies with the basic specifications, your engine won't know the difference

http://www.xs11.com/stories/croil96.htm

[melinx]

Probably more than you ever wanted to know about oil ( 177 pages ) but you can choose which sections to read 

The appendices give a table of oils ( most of them American brands ) and their 'scores'

There is also a section on air filtration.

It seems to take a while to download and you will need Acrobat


http://www.ecoadvanced.net/pdf/motor-oil-bible.pdf

[flash911]

OK, NOW IVE SORTED MY OIL LEAK, WHATS THE BEST FOR MY GSI?

[melinx]

The choice really has to be down to you there is enough information in this thread to make an informed choice

I've just got rid of the GM 10/40 semi synthetic from my 2.6 Diplomat because of problems which may be down to that type of oil, suddenly appearing.

I've considered all the information in this thread and chosen to replace it with Morris Lubricants 15/50 straight mineral oil, it is one of the grades recommended in the handbook.
It's certified to API SL/SJ/CF which is a higher and more up to date spec. than the handbook specifies and it's £12 for 5 litres.

From all the information that is in this thread, I can see no justification for spending £30 or more for oil in a high mileage old design engine, other than it makes a person happy to put it in and the 'rip off' prices keep the oil company advertising executives in luxury

[vauxhalljohn]

just to top up the oil in the dippy , i used the cheap stuff from wilko`s , it runs in my daughters fiesta fine and dandy , but my big old dippy hates it . she hesitates to start once she has cooled down from hot . but only on accasions , but its only started doing this since i added the oil otherwise she was running like her old self before adding named oil .

but i have been meaning to service her since getting her back , will replace oil and filter before winter .

[YasmineLee]

OK, NOW IVE SORTED MY OIL LEAK, WHATS THE BEST FOR MY GSI?

engine oil obviuosly. duh

[flash911]

still as sarky as ever hey missy !!!! 

[man of kent]

Having run cars for more years than I care to think about, all this technology in oil is great BUT it applies to modern engines with much smaller running clearances in the bearings and ring/bore gaps.

For instance, I had a 1932 car and I tried running it on 20W 50. Rattled like hell. It needed straight 30 grade.

Back in the 60's when the first multigrade came out, production engines used to blow up on motorways because the oil was too thin, so be careful.

I would suggest 20W 50 for all high mileage carltons and possibly thicker in the summer!

Dont forget that all oils start as one grade and then they put the additives in. Additives wear out and you finish up with dirty base grade oil which might be just 20 grade! Change the oil when they say ! The good thing about synthetic oil is that it does not change grade, it just gets dirty, hence modern engines run high mileages but with good filters.

[Jimmy]

15 40w Mobil has always been ran in my car since iv had her, done nearly 15k in a year and a half, 92'k-reg just breaching the 86k mark soon and has always ran great stick to what you know i say 

[carlton_mad]

nice to see old threads being revived

[kevinfourlegs]

I run my 2.0 8v Diplomat on GM 15/40 with a genuine filter from the Vauxhall dealer. I use my VODC trade card for a discount.Mileage on mine is approx 144k and it doesn't use/burn oil. I do 6.5-7k a year, mostly short runs and I have the oil and filter changed every 6 months. I never put any oil additive or the like in the engine, only oil. Its a lovely quiet, smooth and clean internally lump.

[melinx]

An interesting article on oil viscosity !

http://www.zddplus.com/TechBrief13%20-%20Oil%20Viscosity.pdf

[melinx]

This one gives some fascinating insights !

http://www.zddplus.com/TechBrief11%20-%20Internal%20Combustion%20Engine%20Lubrication.pdf

The final section of the above article puts a doubt in my mind about whether the plastic sump fairing is a good idea ?