Low SAPS oils: ACEA warning

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Hi all,

many oil manufacturers (especially European and Australians) now provide Low SAPS (low sulfated ash, phosphorus-sulfur). These oils are specifically blended for diesels with particle filters and gasoline engines with 3 way catalytic converters. However oil manufacturers including Castrol, Liqui-Moly, Kroon-Oil etc do also recommend these oils for cars not fitted with these devices.

These oils meet ACEA rating C1 to C3 but also API SM and ACEA A3/B3. The latter makes them suitable for use in virtually any vehicle gasoline or diesel fited or not with a catalytic converter or a particle filter. However the ACEA (European Automobile Manufacturer's Association) has issue a warning about these oils stating that these shouldn't be used in "some" engines:

see page 5 in: http://www.acea.be/images/uploads/files/20090105_081211_ACEA_Oil_Sequences_Final.pdf

On a question addressed at Liqui-Moly regarding one of their low SAPS oils, I have been answered that low SAPS oils are not the best oils for older engines for which they were not targeted.

Some questions:
- What is the issue in using a low SAPS oil in a gasoline engine without 3 way catalyst or particle filter (car is a 1997 Volvo S40 2.0 normally aspirated gasoline engine with "standard" catalytic converter? What is the meaning of the ACEA warning and what does mean "some engines"?

- Does it translate anything into additional wear in the long run?

- Would these low SAPS oil extend the life of standard catalytic converters (non 3 ways)?

Thanks
 
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To the best of my knowledge, all cars sold in the USA since something like 1980 have 3-way catalysts.

The US version of the 1997 Volvo S40 2.0 has a 3-way catalyst. I'm actually a bit surprised that yours does not, even though it is not a US version.

I believe that API SM/ILSAC GF-4 (the current spec for oil in the USA) would be considered low SAPS.
 
Hi Brianl703,

It's well possible my car is fitted with a 3-way catalyst, I have no real idea about that. However the key question is in which engine should these engine oils NOT be used? Actually afaik phosphorus and sulphur are used as EP additive right? Does it mean that low SAPS may provide a lower wear protection compared to conventional oils? Is there specific areas in the engine that require these sulphur phorsphorous additive in large amounts? (I have heard that valve tappets need them....but I think my car is fitted with valve rollers).
 
I think your specific vehicle is new enough that a low-SAPS oil is suitable.

The engines that should not be used with a low-SAPS oil, from what I can determine, are either very old (with valve tappets as you mentioned) or non-automotive applications.

With very few exceptions most newer engines have valve rollers.

Phosphorus and sulfur are used as EP additives, but in low-SAPS oil the phosphorus and sulfur are reduced and other EP additives are used instead.

Quote:
Does it mean that low SAPS may provide a lower wear protection compared to conventional oils?


In older engines, perhaps...but that is not even certain. Here in the USA, API SM/ILSAC GF-4 oil is very widely used even with older engines. This is the most common oil used--your options for non low-saps oil are very limited here.

One correction: The 1997 Volvo S40 wasn't sold in the USA. If it had, however, it would have been equipped with a three-way catalyst.

To answer your other question, a low-SAPS oil should increase the life of both 3-way and 2-way catalysts, as the phosphorous and zinc can poison both types.
 
Thanks for the feedback. Another common "drawback" associated to low SAPS oil is that their TBN is strongly reduced. Non low SAPS lubricants usually have TBN >11-12 while low SAPS oils have TBN<8 often... However these lubricants are often advertised as being able to whistand extended drain intervals. Will the reduction in TBN not cause corrosion or other adverse effect in a vehicle for which these oils are not specifically targeted at? What other additives are used instead of sulphurous-phosphorous EP additive or TBN in these oils?
 
TBN is depleted by use, so a lower TBN oil would, all else being equal, need to be changed more often. Assuming that the oil is changed often enough, the lower TBN would not be a problem.

Moly, boron, and calcium are used in place of the sulphurous-phosphorous EP additive.
 
Originally Posted By: kilou
These oils meet ACEA rating C1 to C3 but also API SM and ACEA A3/B3. The latter makes them suitable for use in virtually any vehicle gasoline or diesel fited or not with a catalytic converter or a particle filter. However the ACEA (European Automobile Manufacturer's Association) has issue a warning about these oils stating that these shouldn't be used in "some" engines


It's not that low SAPS oils are incompatible with your cat. On the contrary, any cat's life will benefit from a low SAPS oil. The problem is that low SAPS oils may not be ideal in terms of wear in older engines, especially in those with flat tappet cams.
 
kilou,

We've been discussing this topic and the general outcome was that if your car manual does not ask specifically for ACEA C2 or C3, do not use it. On my car for example, it is allowed to use ACEA A1, A2, A3, A5, C2, C3. I decided to use ACEA A3 since it does a better engine wear protection.

So did the original dealership by the way
smile.gif
 
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