Buying Oil, Some Basic Advice From Opie Oils

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

This post should help as a basic guide, for more detailed information contact us and we will be happy to help.

So, 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, VW504.00, FORD 913a/b, BMW LL04 etc)

Ignore the marketing blurb on the label it is in many cases meaningless and we will explain later what statements you should treat with skepticism.

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 thin oil in winter and a thicker oil in the 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. I.E. 5w is better than 10w etc

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of an oil and whether it has met or passed the latest tests or whether the formulation is effectively obsolete or out of date.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 of the two specs as it is split (for passenger cars) into two catagories.

S = Petrol and C = Diesel, most oils carry both petrol (S) and diesel © 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 Car Manufacturers on the bottle, the most common in the UK being VW, MB, BMW, Ford or Vauxhall but do not be misled into thinking that you are buying top quality 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 we can give without going into too much depth however there is one final piece of advice regarding labelling.

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

Recommended for use where……………

May be used where the following specifications apply……………

Approved by………………………..(but with no qualification or specification)

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. The cheaper the oil the cheaper the ingredients, lower the performance levels and older the specs it meets so beware!

If you would like further advice then please feel free to ask here or contact us via our website or email.

Simon & Guy

Opie Oils

I'd like to confirm a theory that was once claimed,

that if you dont have to top up your oil your oil isnt working hard enough?!

Basically saying that if your oil isnt burning it isnt the right oil...is this right?

And for someone that only uses the car during the summer...i.e. track days...what is the best oil to use...a 5w 30?

And for someone that only uses the car during the summer...i.e. track days...what is the best oil to use...a 5w 30?

afaik a 5w-30 is way too thin for a track day, especially in summer.

hopefully oilman will come back and agree with me, i reckon he'll recommend a 10w-40 (Silkolene Pro-S or similar).

Yes we tend to recomend either 5w-40 or 10w-50 for track use on a modded TT.

Not familiar with the oil burning thing though.

Cheers

Guy.

Cheers for the reply,

I think what he was trying to say was that if you have say a 15w 60...the oil will burn at a higher temperature than say a 5w 40, therefore, you need to create and find a fine balance between lubrication and the max burning temp,

i.e if there is no need for the oil to burn at such a high temperature then use a 5w 30 e.t.c but for trackdays maybe you will need a 15w 50 unless you can stop and top up evey couple of laps

Now the figures quoted there are just ballpark, so what I'd like to find is the fine balance between lubrication and max burning temp.

To my knowledge, if oil is burning it cant lubricate yeah?

Cheers for the reply,

 

I think what he was trying to say was that if you have say a 15w 60...the oil will burn at a higher temperature than say a 5w 40, therefore, you need to create and find a fine balance between lubrication and the max burning temp,

 

i.e if there is no need for the oil to burn at such a high temperature then use a 5w 30 e.t.c but for trackdays maybe you will need a 15w 50 unless you can stop and top up evey couple of laps

 

Now the figures quoted there are just ballpark, so what I'd like to find is the fine balance between lubrication and max burning temp.

 

To my knowledge, if oil is burning it cant lubricate yeah?

All oils 'burn' or carbonise at around 125 degrees C. This is nothing to do with the oil getting into the combustion chamber and burning with the fuel/air mix, but the maximum temperature thay can operate at. They actually set on fire at about 250 deg C, but at 125 you get a burning smell!

You are correct in saying that once an oil is outside its maximum temperature range it will start to break down and won't lubricate as well, but this is all to do with chains of polymers breaking down and localised pressure combined with the heat.

What you really need to know is how the oil behaves under high shear & pressure loads at high temperatures. This is given by the viscosity index (VI). The higher the VI the better the oil performs and better it will prevent wear. A good synthetic will be 170 to 180 VI. Mobil 1 0W/40 is 187 and Amsoil Series 2000 0W/30 is 195!!!

So for what youre considering here choose a weight of oil (i.e. 10W/40) that is suitable for your application, and make sure it has a high VI.

^^^^ Well put ^^^^

As most people find in the uk its between 5w-40 and 10w-50/15w-50 depending on state of tune and use.

Cheers

Guy.

^^^^ Well put ^^^^

 

As most people find in the uk its between 5w-40 and 10w-50/15w-50 depending on state of tune and use.

 

Cheers

 

Guy.

don,t forget i need engine and gearbox oil saturday plz i will come and find you

Just found the vi for pro-s 10/50 to be 174, thought it would be higher than that compared to other top brands.

Just found the vi for pro-s 10/50 to be 174, thought it would be higher than that compared to other top brands.

Hmmm, maybe not. Perhaps my post was a bit misleading. You really have to compare like for like... i.e. a 10W/50 synthetic vs another 10W/50 synthetic, to find which one is best.

VI is the rate of change in viscosity within a temperature range.

Higher numbers indicate a low change, lower numbers indicate a relatively large change.

The higher number the better. This is the one major property of an oil that keeps your bearings happy. Good synthetics have a high VI & contain little or no polymers, cheap oils are full of polymers, and as such have a high VI.

Obviously a good synthetic straight 40 oil will not change much at all as it is not a multigrade, is synthetic and so should not contain any polymers.

A wide ranging synthetic multigrade, however, will probably change quite a bit if it is for example a 0W/60 as it has to be both very fluid at cold temps and high viscosity at high temps. There's no getting away from the fact that it HAS to change with temperature, and this will cause it to have a lower VI than a straight oil no matter how good it is. This may not be due to the addition of polymers, but because the oil is just behaving the way it should. Most non-synthetic oils would not be able to cover such a wide viscosity range in a multigrade and would be full of polymers to even approach a 5W/30 mever mind 0W/60!

As far a polymers in oils are concerned, Polymer additives are thrown in (more in low quality oils) to give multigrade properties. These are short chain molecules & thin when cold, but expand when hot to thicken up the oil. They’re ok for a while, but the high pressure of cam on cam followers and other areas soon breaks them down so they can’t keep the hot thickness (viscosity) of the oil anymore.

Think of them as something resembling Fusili pasta When dry they are quite small, but as you boil them they expand to a much bigger size. This is similar to what happens in the oil as the expanding polymer chains (Fusili) thicken the oil up. The problem is these can get cut by high pressure areas like the cam, and this makes hot oil drop in viscosity as it ages reducing protection.

Oh ok, i`ll take your word for it, thanks for explaining, and i`ll just keep using the pro-s because i like the colour of it:d

Hi Oilman,

Looking for advice on what oil to use in a 2003 model Mercedes S Class 320 CDI. Currently at 80,000 miles and does around 30k a year so need something that will honour the warranty on the car and not cost the earth. What oil would you recommend for this application and what are the specs I should be looking for in terms of ACPI, grade etc.

Cheers,

Brian.

Hi,

Is your merc on the extended service or does the oil get changed every 10k once a year or so?

Cheers

Guy.

Hi,

 

Is your merc on the extended service or does the oil get changed every 10k once a year or so?

 

Cheers

 

Guy.

Hi Guy,

Will take that on recommendation - looking to do a first service and then not sure what the schedule should be - by onboard computer but not sure the intervals or if it's variable. Mileage figures are projected from last car.

Cheers,

Brian.

This is all very informative

Can I have the tard version;

what oil should I use in a BPU TT

How often should it be changed (time/millage)

What gearbox oil should be used (auto/manual)

This is all very informative

 

Can I have the tard version;

 

what oil should I use in a BPU TT

How often should it be changed (time/millage)

What gearbox oil should be used (auto/manual)

It's all in the FAQs I believe?

Official Toyota servicing schedules are in the downloads area.

Damn you Pete for being so on the ball!

I thought it would be intereting to see what Guy had to say

Damn you Pete for being so on the ball!

 

I thought it would be interesting to see what Guy had to say

Oh bugger. Sorry.

It doesn't really matter, he spouts the same old stuff on every forum anyway where he suggests we should be using £20 a litre stuff and changing it more often than our underpants.

Hey would you think Fords Formula s synthetic oil 5w-40 is ok for a standard J-spec TT...dont think i will be doing any track days in it and its mostley used on motorways...

Cheers

It will be ok, the ford stuff is mineral based so think of it as a good semi synthetic and give it regular oil changes.

Cheers

Guy.

Hey would you think Fords Formula s synthetic oil 5w-40 is ok for a standard J-spec TT...dont think i will be doing any track days in it and its mostley used on motorways...

 

Cheers

Its made by Texaco IIRC, so maybe you can get it cheaper elsewhere.

Should be fine for normal use, especially in the winter.

Hi Guy,

 

Will take that on recommendation - looking to do a first service and then not sure what the schedule should be - by onboard computer but not sure the intervals or if it's variable. Mileage figures are projected from last car.

 

Cheers,

 

Brian.

Hi Guy,

An news on the above?

Cheers,

Brian.

Its made by Texaco IIRC, so maybe you can get it cheaper elsewhere.

 

Should be fine for normal use, especially in the winter.

Thanks guys...as for getting it cheaper it can be cheaper than free:)

It will be ok, the ford stuff is mineral based so think of it as a good semi synthetic and give it regular oil changes.

 

Cheers

 

Guy.

THANKS!!

You say regular...whats that every 4k?