API CG-4/SF or CF-4/SG

[miniac007]

Hi all,

I have the choice between to oils, one API CG-4/SF or one CF-4/SG.

Diesel API and Gas API are in reverse order in term of modernity...

So, which one have more chance to be the best in wear protection for gas/diesel usage ? I am a little disappointed...

Thanks !

 

[Garak]

I'd choose depending upon what the vehicle calls for. If it's looking for a diesel specification, there's likely no reason not to go for the newest specification, in this case the CG-4. If it's a gasoline vehicle, again, there's no reason not to go for the SG. Of course, that's assuming that both oils actually have the appropriate certifications for whatever vehicles they might be used in.

 

[tdi-rick]

Bear in mind that the CG-4 spec was quickly superseded by the much better CH-4 specification as wear problems raised their head with some engines that didn't occur with the CF-4 oils (specifically Japanese diesels)
As a consequence the bulk of Japanese diesel manufacturers will still only allow CF-4 oils for a lot of their engines, even though CH-4 and CI-4 oils showed better wear numbers in practice than earlier blends.

Do the oils sport any ACEA numbers at all ?

 

[Garak]

Originally Posted By: tdi-rick
As a consequence the bulk of Japanese diesel manufacturers will still only allow CF-4 oils for a lot of their engines, even though CH-4 and CI-4 oils showed better wear numbers in practice than earlier blends.

That's a good point. It's uncommon to come across it up here, but one does once in a while.

 

[miniac007]

Originally Posted By: tdi-rick

Do the oils sport any ACEA numbers at all ?


Yes, HDEO ones: The API CG 4/SF and the CF-4 / SG are both ACEA E3


What I don't understand is what in CG-4 works against SG, or what in SG works against CG-4...