Kubota oil

RalphVa

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Got M1 0w30 European C3 diesel in both the Kubota B and the Isuzu generator driver now. No vavle train starvation on them in cold.

I've seen videos our research people did with a transparent valve cover on a Dodge 025 engine in cold room @ -40 C/F. All oils smoked the valve train except 0wxx oil.
 
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TheOldHokie

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My guess is today 's 15-40 full synth will flow much easier than yesterdays non synth 10-30.
Your guess would be wrong. The viscosity grades are comparative measures and have nothing to do with synthetic or conventional. A 10W30 oil is by definition always lower viscosity than a 15W40 oil - always, always, always.

Goo is an exaggeration but Kubota does not recommend 15W40 for use at ambient temps below 15F (-10C). Most OEMs set that cutoff at 32F (0C).

To illustrate here is a viscosity graph of three oils :

BLUE = Shell Rotella 10W30 conventional​
RED = Castrol GTX 15W40 conventional​
GREEN = Delo 15W40 full synthetic.​

For cold weather startup the conventional 10W30 is the clear winner and there is no difference in the conventional versus synthetic 15W40.

Dan

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ruger1980

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Your guess would be wrong. The viscosity grades are comparative measures and have nothing to do with synthetic or conventional. A 10W30 oil is by definition always lower viscosity than a 15W40 oil - always, always, always.

Goo is an exaggeration but Kubota does not recommend 15W40 for use at ambient temps below 15F (-10C). Most OEMs set that cutoff at 32F (0C).

To illustrate here is a viscosity graph of three oils :

BLUE = Shell Rotella 10W30 conventional​
RED = Castrol GTX 15W40 conventional​
GREEN = Delo 15W40 full synthetic.​

For cold weather startup the conventional 10W30 is the clear winner and there is no difference in the conventional versus synthetic 15W40.

Dan

View attachment 82559
Actually the manufacturer I work for recommends 15W40 HDEO down to -16C and 10W** down to -20C.

There is no reason to use a lighter oil in temps most of N America experience unless you are driving for increased fuel economy. I have customers all throughout the country running 15W40 with no issues at all. After all 15W40 HDEO has been the most prevalent HDEO used over the last 50 years and I have not seen any epidemics of engine failures do to lubricants in the timeframe.

The statement that valve trains will smoke if using a 15W oil is fantasy. I have other customers with 60-80K hrs. on their machines running 15W40 HDEO and never had an engine failure. To be honest engine failures due to lubricant type or quality are rare. The vast majority of engine failures involving lubricant are due to lack of or contaminated lube and that is an undisputable fact.
 
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Mark_BX25D

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If you're trying to "stretch" the capabilities of an oil you don't want to mix it with another brand or even a different formulation from the same company. As it will revert to the lowest common denominator

That's what's technially known as an "OWT".


Old Wive's Tale. As in, pure bunk. Nonsense. No factual basis.
 
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Mark_BX25D

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The vast majority of engine failures involving lubricant are due to lack of or contaminated lube and that is an undisputable fact.

That's why the most important oil advice is, "Use some." ;)


Everything else is niggling about details.
 
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Dieseldonato

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Got M1 0w30 European C3 diesel in both the Kubota B and the Isuzu generator driver now. No vavle train starvation on them in cold.

I've seen videos our research people did with a transparent valve cover on a Dodge 025 engine in cold room @ -40 C/F. All oils smoked the valve train except 0wxx oil.
And you see routine temperatures of -40*c where you live? Hitting 0 let alone negative is pretty rare here. Teens yep seen that, but honestly, a blanket statement to cover the entire world?
 

WoodKutter

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Got M1 0w30 European C3 diesel in both the Kubota B and the Isuzu generator driver now. No vavle train starvation on them in cold.

I've seen videos our research people did with a transparent valve cover on a Dodge 025 engine in cold room @ -40 C/F. All oils smoked the valve train except 0wxx oil.
I respect that we all have different views. I see nothing in Kubota oil specs. or Mobil 1 stating 0-30 with or without the c-3 rating is recommended or even adequate in a Kubota diesel. Please educate me/us if I'm incorrect.
 

TheOldHokie

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I respect that we all have different views. I see nothing in Kubota oil specs. or Mobil 1 stating 0-30 with or without the c-3 rating is recommended or even adequate in a Kubota diesel. Please educate me/us if I'm incorrect.
Its a grade 30 oil just like the recommended 10W30 but with a higher viscosity index (the 0W part) for better cold weather cranking and flow. I think that qualifies as adequate viscosity wise.

It is a ACEA C3 service class that falls short of the API CK4 service specified by Kubota. That makes it a passenger car and light truck diesel oil not a heavt duty diesel engine oil as specified by Kubota . So I would call it inadequate in that regard.

There are many better choices for that price point. For example Mobil Delvac 1 5W30 is a CK4/ACEA E9 heavy duty diesel engine oil that would check all of the boxes.

Dan
 
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RalphVa

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I respect that we all have different views. I see nothing in Kubota oil specs. or Mobil 1 stating 0-30 with or without the c-3 rating is recommended or even adequate in a Kubota diesel. Please educate me/us if I'm incorrect.
If 10w30 is mentioned (and it is), then 0w30 and 5w30 are fine, too.

15w40 is mentioned. Then 0w40, 5w40 and 10w40 are fine, too.

What is mentioned is the minimum. For instance, 20w40 is a no go. I'm really surprised even at the 15w40. I'd think both 10w40 and 10w30 should be the minimums.

20w is also mentioned. That means that 0w20 and 5w20 are all good. However, you won't find any diesel oils in 20w.
 

TheOldHokie

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If 10w30 is mentioned (and it is), then 0w30 and 5w30 are fine, too.

15w40 is mentioned. Then 0w40, 5w40 and 10w40 are fine, too.

What is mentioned is the minimum. For instance, 20w40 is a no go. I'm really surprised even at the 15w40. I'd think both 10w40 and 10w30 should be the minimums.

20w is also mentioned. That means that 0w20 and 5w20 are all good. However, you won't find any diesel oils in 20w.
The list does not mention SAE 20W - it mentions SAE 20.

Dan
 

RalphVa

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No Ralph. As an oil professional you should kbow the difference between 20W and 20.

Dan
They're the same. We used to just call it 20w, but with the xxwxx stuff, it is NOT 20wxx. I'd have to look up the specs on SAE 20 and some more research to determine what it really is. It's likely something like 08w20. They just don't test the low temperature part of an SAE 20.
 

TheOldHokie

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They're the same. We used to just call it 20w, but with the xxwxx stuff, it is NOT 20wxx. I'd have to look up the specs on SAE 20 and some more research to determine what it really is. It's likely something like 08w20. They just don't test the low temperature part of an SAE 20.
That is utter BS.

Here are the current SAE J300 requirements including the ASTM test methods to be used for measurements. . The xxW grades are shown in columns 2-4. and xx grades in the columns 4-6, The only overlap between xxW and xx grades is column 4.

A multi-grade oil meets exactly one of the xxW requirements AND exactly one of the xx grade requirements.

A monograde oil meets only one of the xxW requirements or one of the xx requiremnts but not both.

SAE 20 and SAE 20W are entirely different grades.

SAE J300 also specifies the ASTM, test methods to be used for the measurements. There is no such thing as a 08W20 multograde oil.

Dan

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TheOldHokie

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Great. Now I want a mult-o-grade oil.

First it was Amsoil mult-o-signatures oil and now this. I can't keep up.
I went yhrough Amsoil product promotion school but flunked the final exam when I passed the polygraph test......

Dan
 
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RalphVa

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That is utter BS.

Here are the current SAE J300 requirements including the ASTM test methods to be used for measurements. . The xxW grades are shown in columns 2-4. and xx grades in the columns 4-6, The only overlap between xxW and xx grades is column 4.

A multi-grade oil meets exactly one of the xxW requirements AND exactly one of the xx grade requirements.

A monograde oil meets only one of the xxW requirements or one of the xx requiremnts but not both.

SAE 20 and SAE 20W are entirely different grades.

SAE J300 also specifies the ASTM, test methods to be used for the measurements. There is no such thing as a 08W20 multograde oil.

Dan

View attachment 82677
The 20W is for like a 20w50 oil, for the 20W part. SAE 20 is just 20 weight oil. Neither above nor on line could I find any spec on VI or a lower temperature spec for it to know what xxw20 it is.

The first number is NOT the grade of the oil. It is for its specification at some lower temperature. The 2nd number in the xxwyy spec is the grade of the oil at operating temperature, e.g. 100 C.

I've read where some of you have called 5w30 oil a 5 grade but acts like a 30 grade at operating temperature. No. It's a 30 grade oil that meets the low temperature spec for a 5 grade and likely has about 140-190 VI.