Oil specifications explained


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’s important to know what the oil’s intended purpose is.


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 oil’s cold temperature/cold start performance. The 40 in a 10w-40 simply means that the oil must fall within certain viscosity limits at 100°C. 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°C etc. Your handbook will specify whether a 30, 40 or 50 etc is required.


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of the oil and whether they have met or passed the latest tests, or whether the formulation is effectively obsolete or out of date.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 categories. 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.

SN – Introduced in 2010 – The API SN category is an improvement over the API SM category in the following areas: • High temperature deposit protection for pistons • Better sludge control • Better seal compatibility • After treatment compatibility

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 and/or protection for modern cars.

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 – modern 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 sulfur 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 sulfur 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 % sulfur. 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.

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

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 (Sulfated Ash, Phosphorus and Sulfur). Unlike API the ACEA specs are split into performance/application categories 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- Petrol and Light Duty Diesel engines, based on A5/B5 low SAPS, two-way catalyst compatible.

C2- Petrol and light duty Diesel engines, based on A5/B5 mid SAPS, two-way catalyst compatible.

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

Note: SAPS = Sulfated Ash, Phosphorous and Sulfur. Put simply, A3/B3, A5/B5 and C3 oils are the better quality, stay in grade performance oils.


Japanese motorcycle manufacturers found the limits demanded by the API TC specifications too loose. Oils meeting the API TC standard still produced excessive smoke and could not prevent exhaust blocking. Therefore, the Japanese Engine Oil Standards Implementation Panel (JASO) introduced the following specifications:

JASO FA Original spec established regulating lubricity, detergency, initial torque, exhaust smoke and exhaust system blocking.

JASO FB Increased lubricity, detergency, exhaust smoke and exhaust system blocking requirements over FA.

JASO FC Lubricity and initial torque requirements same as FB, however far higher detergency, exhaust smoke and exhaust system blocking requirements over FB.

JASO FD Same as FC with far higher detergency requirement. Find out more about JASO’s 2T specifications from their website.

JASO has created its own 4 – Stroke motorcycle standard – JASO T 903 – which now has three grades – MA, MA1 and MA2 – to facilitate the choice of lubricants that are specifically developed for wet clutch applications.

JASO MA2 offers the most efficient friction levels to guarantee the clutch engagement during the three riding modes: starting, acceleration and constant speed

JASO MB grade oils are classified as the lowest friction oils among motorcycle four-cycle oils. Not to be used where a JASO MA grade oil is required.


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(only approved specs for Lebanon) and LL04, LL12, LL14+, LL17 FE are more up to date oils but not applicable on all BMW engines or countries.

PSA- Peugeot Citroen specs, example: PSA B71 2296 Peugeot/Citroën engine oil specification introduced in 2009. General specifications: ACEA A3/B4 + additional PSA tests.

Renault- RN0720, Renault engine oil specification; introduced in 2007 General requirements: ACEA C3 + additional Renault demands. The latest specs from Renault is the RN17 that covers most if its recent models.

If in doubt of the oil to use on your car go to www.motul.com and click on Oil Selector.