Yanmar 1GM10 engine oil - API categories

[slawosz]

Hi,
I got of ebay original Yanmar oil, turned out category is Cl-4. The manual, downloaded from the Yanmar website says do not use CG-4, CH-4 categories and CI-4 is compatibile with those - I wonder if I could damage the engine using CI-4 category?

 

[VicS]

Hi,
I got of ebay original Yanmar oil, turned out category is Cl-4. The manual, downloaded from the Yanmar website says do not use CG-4, CH-4 categories and CI-4 is compatibile with those - I wonder if I could damage the engine using CI-4 category?

First thoughts
The latest manual I have found, 2018, post dates the introduction of the CI-4 specification by a good margin and does not prohibit its use.
The manual specifies a tbn of greater than 9. ITYWF CI-4 has a tbn of 13

I'd assume its Ok.

It'll be interesting to see Vyv Cox's opinion

 

[slawosz]

Thanks! I read Vyv Cox's website and in theory, Yanmar introduced CI-4. But I am confused - although I presume most of the people buy cheap oil in Halfords, Tesco and those have relatively high API as well. We don't hear much about excessive engine wear.

 

[vyv_cox]

I think CI-4 is a good oil for older engines as it recognises that the sulfur content of diesel is now so much lower.

Quite surprised to see that its TBN is as high as 13. Last time I looked it was 8 but maybe it is higher to comply with the API-CG and CH specs. Unfortunately it is often not easy to find the actual API spec, we see what manufacturers choose to tell us.