Can an oil meet ACEA C3 and ACEA A3/B4?
I'm noticing more and more oil manufacturers are selling oil as ACEA C3 and ACEA A3/B4. I was always under the assumption they were mutually exclusive?
ACEA C3 Oils Being Sold As Meeting ACEA A3/B4
- Thread starter Bailes1992
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They just label it like that...
Since both has HTHS @3.5 min...and everything else being "equal" (lets say)... Formulators can produce ashless C3 oil that can protect as good as A4/B4 with his "ash" add pack...
Except that Cx oils are inferior at long drain intervals...since they have lower TBN numbers because of its ashless add pack technology...
The oils are mutually exclusive but have some similarities, both are PCMOs with a HTHS above 3.5 cP and a Noack below 13%
A3/B4 requires a TBN above 10 and a Sulphated Ash between 1.0 and 1.6 %
C3 requires a TBN above 6 and a Sulphated Ash below 0.8 %
So A3/B4 is the high SAPS version of the oil, while C3 is the mid-SAPS version of the oil.
For low sulphur fuel and reasonable oil change intervals (OCI), their usage overlaps, but they can Not be the same oil.
BTW the low-SAPS version is C4.
He summed up with better words/explanation 
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Simple answer is No, not any more.
I mentioned this in another thread, when C3 was introduced there was an overlap ACEA specs that allowed the same oil to carry A3/A4 and C3. Newer specification eliminated this overlap.
If there are any current ACEA oils claiming A3/B4 and C3 together then they are following obsolete specs or incorrectly labelled.
Can't remember the exact name, but I have some PP Euro diesel stuff that is C3 and carries the vw502 approval, but it's NOT an A3/B4 oil. Talk about confusing..
I always thought a vw502 oil by definition was a long drain oil seeing how they are typically A3/B4. Certainly not the case with a C3 approval as well.. I just use the stuff for top offs when the OCI is nearly over.
Originally Posted By: dlundblad
Can't remember the exact name, but I have some PP Euro diesel stuff that is C3 and carries the vw502 approval, but it's NOT an A3/B4 oil. Talk about confusing..
I always thought a vw502 oil by definition was a long drain oil seeing how they are typically A3/B4. Certainly not the case with a C3 approval as well.. I just use the stuff for top offs when the OCI is nearly over.
VW502 can be low saps and is old enough that it existed in the day when A3/B4 could be low saps too. VW have recently revised this spec so that VW502 must be high SAPS. Licenced Low SAPS oils can keep their license until it expires.
You'll never see a major manufacturers claiming both specs as they are mutually exclusive. Some small oil producers do claim both the C3 and A3/B4, however that was possible only with ACEA sequence 2008 as min TBN for B4 spec has risen since. So either manufacturer claim something like A3/B4-08 and C3-08 ( obsolete in nature by now and not permitted by ACEA- only current spec is relevant) or it does not disclose sequence year at all. In 08 sequence min TBN for A3/B4 was 8, so some C3 indeed qualified. However this is not the truth now. Do not buy oils that aren't legit in their claims/approvals and do not encourage false play by some oil producers. Rules are clear and simple and there to be followed.
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Originally Posted By: supercity
VW502 can be low saps and is old enough that it existed in the day when A3/B4 could be low saps too. VW have recently revised this spec so that VW502 must be high SAPS. Licenced Low SAPS oils can keep their license until it expires.
https://www.lubrizol.com/Lubricant-and-F...es/ACEA-A3B4-10
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The introduction of a minimum Total Base Number (TBN) of 8.0 mgKOH/g affects the number of ACEA sequences that can be combined with ACEA A3/B4-08. Prior to ACEA 2008, depending upon the performance of the engine oil, it was possible to combine ACEA A3/B4 with a number of other sequences including ACEA C3. However, as engine oils meeting the ACEA C Sequences are formulated to a lower sulphated ash level they tend to deliver a TBN of less than 8.0 mgKOH/g. Therefore, with the introduction of ACEA 2010 it is unlikely that engine oils meeting the ACEA C sequences will also be able to meet ACEA A3/B4.
Originally Posted By: Garak
Originally Posted By: supercity
VW502 can be low saps and is old enough that it existed in the day when A3/B4 could be low saps too. VW have recently revised this spec so that VW502 must be high SAPS. Licenced Low SAPS oils can keep their license until it expires.
Yes, it's certainly true with some grandfathered specs, but, generally speaking, it pays attention to note what the current ACEA sequence is that should be applicable.
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