How does Dexos 2 compare to A5/B5?

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I have always heard that European oil standards (ACEA) are more rigorous than American API standards. I can see that for SN, SN plus, SP.

But playing around with the lubrizol oil spec comparison tool, I thought that the dexos 2 standard came pretty close.

Are there other categories, than those listed in the tool, whereby A5/B5 shows itself to be significantly better? Or has dexos 2 closed the gap?

chart.jpeg

One more question--"aftertreatment compatibility"--does that mean measures like zinc limits, to prolong cat life?
 
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ACEA is not approval. It is specification set up by association of manufacturers (that is what ACEA means). It is kind of starting point for manufacturers approvals in Europe. Dexos is approval specification by single manufacturer. Comparison should be between Dexos and let's say BMW LL01FE or MB229.61.
 
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In theory, an A5/B5 oil is much less restricted on how much ZDDP & over based metallic detergent it can contain (hence the after treatment compatibility bump on the Lz chart). The reality however is that no commercial A5/B5 oil is ever lively to be formulated with over 1000ppm of Phosphorus or the maximum permissible 1.6% Sulphated Ash. It's just the way it is...
 
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In theory, an A5/B5 oil is much less restricted on how much ZDDP & over based metallic detergent it can contain (hence the after treatment compatibility bump on the Lz chart). The reality however is that no commercial A5/B5 oil is ever lively to be formulated with over 1000ppm of Phosphorus or the maximum permissible 1.6% Sulphated Ash. It's just the way it is...
Hey you're back.
 

paulri

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OK, here is the spider web chart of Dexos2 vs. C3:
Dexos2 vs. C3.jpeg

Within these parameters, Dexos2 looks like it is a slightly higher standard.

OK then, so has Dexos closed the quality gap between European oils and lower quality American oils? Or are there other criteria that would still make A5/B5 or C3 a higher standard?
 

paulri

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The grey areas (indicating where Dexos2 specs are higher)--wear protection and oxidative thickening--cover more area than the two areas where C3 has an advantage--soot thickening and piston deposits. I'm not sure how significant the advantage in fuel economy is... I don't doubt that this chart is simplified. Perhaps "slightly higher standard" is too much to conclude from that. At any rate, if it is simply a matter of one spec being better in one way, the other spec being better in another way, then perhaps Dexos2 has closed the quality gap?


Not sure how you came to this conclusion. Based on this chart alone (which is somewhat of a simplified view), it looks like Dexos2 is better in some areas while C3 is better in other areas.
 
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OK then, so has Dexos closed the quality gap between European oils and lower quality American oils?
I don't know about closing the gap completely (I haven't studied the Afton handbook), but it for sure has reduced that gap when you compare basic API SN/SP oil to Dexos2 oil.

And just like an MFG spec such as Dexos2 exceeds North American industry spec (API SN/SP), Euro MFG specs such as Porsche C40 exceed European industry specs (ACEA C3), so again, you should probably be comparing one MFG spec to another MFG spec, and not one MFG spec to some industry standard, just not using Lubrizol chart as the tool. :)
 
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paulri

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Thanks for emphasizing that point. OK so its not a good tool for comparing two separate specs. Wemay, you used a very diplomatic way to let someone know he's barking up the wrong tree. :giggle:

The latest Afton I have is 2016. I see here (https://bobistheoilguy.com/forums/threads/afton-specification-handbook-september-2019.321469/) that it was updated for 2019, but the link Gokhan posted in the OP is dead, and I couldn't find it at their site.

OK in that thread, just scroll down Gokhan's post of 31 July 2020 and the link there works.
 
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Yes, good point.

One's probably better off reviewing and comparing more detailed testing requirements for both Dexos2 and ACEA C3 in Afton Handbook instead.
Absolutely. Even the 360.Lubrizol specifications tab will give you some of the important requiremets...






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The grey areas (indicating where Dexos2 specs are higher)--wear protection and oxidative thickening--cover more area than the two areas where C3 has an advantage--soot thickening and piston deposits. I'm not sure how significant the advantage in fuel economy is... I don't doubt that this chart is simplified. Perhaps "slightly higher standard" is too much to conclude from that. At any rate, if it is simply a matter of one spec being better in one way, the other spec being better in another way, then perhaps Dexos2 has closed the quality gap?
Dexos is specification for one manufacturer. ACEA is not specification for a single manufacturer. Think of ACEA as API. Again, if you want to compare, compare MB229.52, VW 504.00/507.00 or BMW LL04 with Dexos 2.
 

paulri

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I have always thought that they were single-test specs, dealing with one specific issue with their engines, that oil might need. I see (in the Afton handbook) that they are a group of specs.

Dexos is specification for one manufacturer. ACEA is not specification for a single manufacturer. Think of ACEA as API. Again, if you want to compare, compare MB229.52, VW 504.00/507.00 or BMW LL04 with Dexos 2.
 
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I have always thought that they were single-test specs, dealing with one specific issue with their engines, that oil might need. I see (in the Afton handbook) that they are a group of specs.
Single test spec? Noooo. MB229.5x are most comprehensive approvals. VW504.00/507.00 are ridiculously hard to achieve. BMW LL04 have extreme oxidation requirements. But they all have very stringent multiple requirements.
 

SR5

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I’ve never seen a Dexos2 oil that wasn’t also ACEA C3, you always get both as far as I can see.

Many Euro OEM specs start by saying the oil must first meet a certain ACEA spec, then they add multipe additional requirements on top of that. No need to reinvent the wheel.
 
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