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API oil classification question

Ray Haefy I've got a new B2320 that's coming up on 50 hours. The manual is confusing to me where API classification is concerned. Can I use Delo 15W-40 with a CJ-4 API rating or should I look for something with a lower rating. I believe the B2320 does not have an EGR valve according to a chart in the manual. The manual recommends a lower API rating for engines "except external EGR". I know what an EGR valve is. Thanks for any advice.


SAR Use the Delo 400 15w-40, The API...
( American Petroleum institute )CJ4 class is fine.
The higher API spec the better the lube.
Always use the better lube.
"S" suffix is for gasoline engines.
"C" suffix is for diesel engines..CJ4
As for a EGR valve, i've never seen one on a
diesel, however I guess that could happen.

Ray Haefy Thanks for the advice SAR. I don't see an EGR valve under the hood but the manual talks about engines other than mine that have either an internal EGR valve or an external EGR valve. Mine falls under the catagory of "none". It also states that CJ-4 is intended for DPF (diesel particulate filter) type engines and cannot be used on this tractor. It's very confusing. I knew that about API classifications being higher the better but since this is my first diesel I wanted to ask. Thanks again.


larry caldwell Check the Kubota lube schedule website. It's not true that the higher the better. There is one spec Kubota says not to use, and I think it is CJ.
Ray Haefy Thanks Larry. I checked that lub schedule on the company site and am more confused than before. Under oil classifications it has two rows: one for engine models D902-E3B-XXXX and another for D902-E2B-XXXX. In both columns it states do not use CJ-4. My B2320 engine model is D1005-E3-D22. This may be an old chart that dosen't include the B2320 series engine but like you said it does say do not use CJ-4 oil. I may just use the company oil the first time around as well as the two filters. Thanks all.


Jim If you use the kubota brand oil, it's bottled
by the lowest bidder, so you don't know what the
heck your getting. Use the Chevron Delo 400
15w-40 or Shell Rotella 15w-40.
It is true, the higher api specs the better
the lube. The lower the specs the less additives
it has. The two brands and viscosity above is
approved for your engine. And if you want to add
many years to the life of your engine, add a
bottle of STP. Specs change from time to time
and I have found many mistakes in this area.
Don't use this.....then later the specs drop
the don't use this, turns out to be fine.

Jerry Been a Kubota dealer for 28 years so don,t want to tell you what oil to use but I issues with any 15 w 40..Don,t like the 40 wt even when hot. 10w 30 is what Kubota wants..
farmm This oil thing is a can of worms so to speak. STP seems to be the way to go whatever oil you put in a small diesel engine. My engine has been quieter, more powerfull after I used STP.
William Correct Farmm. I can't figure why there is such
a can of worms on oil. I know the government is
on the manufactures to increase fuel economy.
That is why they recommend the light viscosity.
It will give a small amount of fuel economy increase, on the other hand it will shorten the
life of the engine. The bad part is people just
don't seem to get it. The light viscosity does
have enough lube to lubricate properly, however
it lacks the proper cushion for parts banging
together. If a person is nuts enough to use the
5w-20 or 10w-30 viscosity the best thing they
can do is add a bottle of STP. Another thing
that gets to me...people say what weight oil
should I use, (WEIGHT) Isn't correct, weight
isn't even in the lube vocabulary. The correct
term is viscosity. 10w-30...the W stands for
winter flow. that is how fast the lube will
flow at a certain temp. and you here Techs and
even owners of shops use the term WEIGHT. That
tells me to head for some other shop. Just for
the truth of it, I use Chevron Delo 400 30w
with 1 bottle of STP, and I don't have to worry
about thermal viscosity break down in hot heavy
operating conditions. All this is why some people
get long life and some don't get service at all.
some are in the know and some just can't understand.

WHAT KUBOTA WANTS !! WHAT KUBOTA WANTS; OKAY, this is out of my owners
manual; Engine oil...API service CD, CE, or CF.
TEMPS BELOW 32 degrees F. 10W, 10W-30, 10W-40
which are all 10 viscosity.

TEMPS FROM 32 degrees F. to above 77 degrees F.
10W-30; 10W-40; 20W , OR SAE 30W,

NOTES FROM SHELL OIL; 10W-30 for diesel is being
slowly fazed out, too light viscosity for diesel.
15w-30 and 15w-40 is taking the place of 10w-30.
15w-30 and 15w-40 is considered a common light
duty lubricant for light every day use. NOT

Shell wouldn't comment on the STP,
However you can believe I sure use it.

farmm Thanks William , I have never gone into this light multiuse oil myself. My cars are happy for not going this route, I always use a heavier oil than recommended and I have 3 Ford vans over 160000 miles and oil consumption is not a problem, the rest of the car dies before the engine does.
Ray Haefy I just checked and found out that Shell, Delo and Mobil 15W-40 all are API CJ-4 so I guess the Delo I have will be what I'll use. I also agree on the STP (Stay-Together-Please). Thanks all! Great forum.


Ray Haefy Thanks for your advice. My original question was about the API but the topic has changed to viscosity. I have figured out that most of the oils available are CJ-4. Want to get a good thread going? just mention an oil question! :)


API CLASS API... As time passes, the API will change.
it starts off with api ca, cb,cc, cd and so
on. It finally will have the cj-4. The API may
only have cj-4 showing, however it will contain
all the api service from the start service of
ca and follow through to cj-4, all this will
be additives to make the lube better or in a
higher class to help protect the latest products,
and it will also help protect the older products.
so unless you have some very old oil stock on hand, any oil you purchace new will contain those
api services, unless it happens to be some sort of
low priced no name product.
The c api is for diesel,
The s api is for gasoline.
If the oil has both c service and s service
then the oil is great for both gas or diesel.

SAR Totally correct on the API service, your machine
may only call for api up to cf in the owners
manual, that is because at the time of print that
would be the highest api service you could have.
That doesn't mean you have to stop at that point
just because the api has become rated higher.

Ray The manual says don't use CJ-4. "The CJ-4 engine oil is intended for DPF (Diesel Particulate Filter) type engines, and cannot be used on this tractor."
farmm Tractor manuals are out of date by the time they are published. I would ask the dealer where to find 5 year old oil to use in my tractor. That is not going to happen. Just use the new oil off the shelf and don't worry.
Mike Good article on 10W30 for Diesel. It is not going away.

Joe Jelemensky Just wanted to update this thread, concerning the API CJ-4 references. The Kubota support page, (, now says CJ-4 is fine for all engines and has this footnote: "**As of May 2012 this information supersedes all previous publications regarding the use of CJ-4".


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