A3/B3 vs A3/B4, big difference or irrelevant?

[FCD]

For an older engine, that when new would have simply required a 10W-40 meeting API SF/SG.
What real difference is there between A3/B3 and A3/B4?
If it's of any help the car in question has Mechanical fuel injection, and tends to have relatively high fuel dilution, would B4 be better than B3 for this?

 

[slacktide_bitog]

A3/B4 requires a higher TBN (>= 10.0) than A3/B3 (>= 8.0), which means it can usually handle a longer OCI

But even the latest A3/B3 is better than any SF/SG available in the 80s

 

[FCD]

So B4 only requires a higher TBN and nothing else?

 

[JAG]

Differences exist for sulfated ash limit, minimum TBN, some performance limits are more strict for A3/B4, and that category also requires some tests that A3/B3 doesn’t have to go through.
http://www.acea.be/uploads/news_documents/ACEA_European_oil_sequences_2016.pdf

A3/B4 is slightly to moderately more difficult to meet. Neither are as difficult as some manufacturer approvals like MB 229.5, 229.51, 229.52; VW 504/507; Porsche A40, C30.

 

[SR5]

Originally Posted By: FordCapriDriver
So B4 only requires a higher TBN and nothing else?

B4 requires higher TBN (min 10 Vs min 8) and lower wear
- Cam wear outlet average < 140 micron (B3) Vs < 120 micron (B4)
- Cam wear inlet average < 110 micron (B3) Vs < 100 micron (B4)
- Bore polishing < 3.5% (B3) Vs < 3.0% (B4)

But, the B3 may pass these wear tests, and it may just be TBN and marketing / price point placement that is the real difference. That is for you to decide. I recently purchases some new Castrol UltraClean 15W40 (SN/CF & A3/B3) semi-synthetic at $15-$16 for 5L, and I look forward to using it. It should be a lot better than the old SF - SG oil that we use to use.

 

[Kamele0N]

Acea A3/B4 is base for approvals like MB 229.5 LL-01 A40 (high saps)

Acea Cx (x =3,4 high HTHS) is base for low/mid saps specs like MB 229.51 LL-04 C30

 

[SR5]

FCD,

Here is a previous thread comparing Shell Helix HX5 15W40 mineral (SN & A3/B3) to Shell Helix HX7 10W40 semi-synthetic (SN & A3/B4)
https://bobistheoilguy.com/forums/ubbthreads.php/topics/4146538/

 

[FCD]

Ah thanks SR5.
Just thinking about wether i should keep using a HDEO in my Escort or move to a 10W-40 Semi-Syn PCMO with a decentm amount of Zinc in it, specifically Comma X-flow Type XS, i could get it for the same price as the HDEO i am using.