Making sense of API class

westbrooklawn · Apr 15, 2011

OK... time to change the oil in my Kubota L3400. owners manual says use oil class CF for High sulfur fuel, or CF, CF-4, CG-4, CH-4 or CI-4 with low sulfur fuels. I have 3 unopened gallons of Delo 400 LE, API CJ-4. The label on those containers shows it "compatible" with CI-4plus, CI-4, CH-4, CG-4, and CF. I am assuming that "compatible" means it can be used "in place of"? If that is the case, what I have should be fine. Am I reading this right?

piller · Apr 16, 2011

Always a confusing subject. lot's of threads about it here on TBN.

In my opinion you are reading it right though. Decide for yourself however, or ask Kubota Corporation. I'm using CJ-4 in my tractor, along with ULSD fuel, and I'm not extending the oil change intervals. My Kubota manual says CG-4, CF-4, or CF with low sulfur fuel (these API ratings are now obsolete, CJ-4, CI-4, and CH-4 are current).

From the Welcome To The API Website site:
"API CJ-4 oils exceed the performance criteria of API CI-4 with CI-4 PLUS, CI-4, CH-4, CG-4 and CF-4 and can effectively lubricate engines calling for those API Service Categories. When using CJ-4 oil with higher than 15 ppm sulfur fuel, consult the engine manufacturer for service interval."

Good luck!

hooked up · Apr 16, 2011

westbrooklawn said:
OK... time to change the oil in my Kubota L3400. owners manual says use oil class CF for High sulfur fuel, or CF, CF-4, CG-4, CH-4 or CI-4 with low sulfur fuels. I have 3 unopened gallons of Delo 400 LE, API CJ-4. The label on those containers shows it "compatible" with CI-4plus, CI-4, CH-4, CG-4, and CF. I am assuming that "compatible" means it can be used "in place of"? If that is the case, what I have should be fine. Am I reading this right?

I went through this last year with my ZD331. It took a long time to get a straight answer from Kubota, but I got it. To summarize, you are fine to use CJ-4 IF you are using ULSD fuel. if you are not using ULSD you need to shorten the change intervals. What fuel are you using?

Hope this helps. if you would like me to email you my correspondance with Kubota, just Pm me and I'll send it to you (or anyone else that would like it).

westbrooklawn · Apr 16, 2011

Thanks for the replies... I am using ULSD so it should be fine...

daman1 · Apr 17, 2011

westbrooklawn said:
Thanks for the replies... I am using ULSD so it should be fine...

CJ-4 oil's have outstanding soot handling capability's and will protect your Kub perfectly fine.

fieldserviceengineer · Apr 19, 2011

""API CJ-4 oils exceed the performance criteria of API CI-4 with CI-4 PLUS, CI-4, CH-4, CG-4 and CF-4 and can effectively lubricate engines calling for those API Service Categories."

The above statement earlier posted coming from an API website. Beginning late 2007, Cummins ISX (15L truck engine) began to experience lube oil filter plugging complaints. In 2007 the CJ-4 oil was the recommended oil for 2007+ ISX and other engine oems who were emissions compliant to the 2007 Tier. Customers who continued to use CI-4 oil had much less complaints on filter plugging and oil change life. I worked on this for two years. Just because the API says it is so....don't make it so! API while a technical arm is also a marketing organization that promotes their latest specifications. They have their own agenda.

Stay with CI-4 or CI-4+. Customers with catalyst reduction mufflers did not experience the dire warnings that Cummins made about using a non-recommended oil.

CJ-4 oils have reduced levels of ZDDP antiwear additive and reduced levels of TBN additives. Few ISX engines were able to achieve extended drain targets due to the reduced TBN additive levels. While you may not be interested in extending drain intervals, I say the above to illustrate that just because API says it is so.....it ain't necessarily so!