Why semi-synthetic??

[Oxman]

Needing to supply my local Mercedes Benz dealer, he has insisted that I supply MB 228.5 spec oil. Fair enough, but I see that this stipulation only carries an API spec of CF, whereas the "lower" MB228.3 is a CI-4?!
My question is, what is the benefit of group 11 base oils if the API specification is lower?

 

[m37charlie]

Most 228.5 oils are ACEA E7 as well as all being E4; whereas 228.3 oils are just E7. An E4/E7 oil has superior characteristics to just an E7. I have the 228.x test specs at home, I will send a link in about 8 hrs.
It so happens that most 228.5 oils are Group III oils whereas 228.3 oils are Group II or I/II mixes.
What vehicle and engine are you referring to?
The older 366A/LA engines require a 228.3 at most, IMHO.
API specs mean little to nothing when dealing with a European engine sold outside the North American market, compared with ACEA - again, IMHO. Below is the list of 228.5 oils.
http://bevo.mercedes-benz.com/bevolisten...ent_action=show
You can navigate to page 223.2 and see what oil spec is required for your motor.
The oil I use in my gazillion dollar U500 is only CF but also ACEA E4/E5. It's a 5W40 so it's not needed for Botswana. I use it because it was the only 228.5 5W40 I could get.

Charlie

 

[m37charlie]

p.46 of:
http://www.w124performance.com/docs/general/oil_rating_info.pdf
You can see ACEA E4 and E7 specs on
http://www.acea.be/images/uploads/files/20090105_081211_ACEA_Oil_Sequences_Final.pdf
They are as comprehensive or more so than API; but different.
All 228.5 oils are E4, some also E5 or E7; all 228.3 oils are E7.

Charlie

 

[Oxman]

Many thanks Charlie, makes more sense now.
Couldn't log on to your links for w124 & ACEA, but got all the info I need from the Lubrizol site.
My customer only wishes to adhere to procedures as laid out by the OEM, but I was curious as to what the difference is.
Here in Africa, we have had been API force fed, hence I did not know that ACEA is the predominant standard for our part of the world.
Thank God for BITOG!