Engine oil: 5W-40 too broad?

JackJ

Member

Equipment
BX1870-1
Mar 14, 2016
264
3
18
Indiana
I hate to bring up an oil topic, but.....

I'm getting ready for my 50 hr service on my new BX1870. I've ordered Kubota filters and SUDT2. I'm sure I'd be fine with Kubota engine oil, too, or any other name brand oil that meets the spec. But I've long been a Mobile 1 user in my vehicles, and while I can't say with any certainty that the extra cost is justified by the performance, I'm willing to pay more just for the peace of mind that I didn't try to cut any corners in keeping my engine well lubricated.

Problem for me is that it's hard to find a diesel engine oil that meets the Kubota viscosity specs:
Below 0°C (32°) SAE 10W, 10W-30 or 15W-40. 0 to 25°C (32° to 77°F) SAE20, 10W-30 or 15w-40. Above 25°C (77°F) SAE30, 10W-30 or 15W-40​

Rotella T6 seems to be the most commonly recommended diesel synthetic, but apparently only comes in a 5W-40. Same for Mobil 1 Turbo Diesel Truck. Amsoil has some, but I'm turned off by their sales and marketing mechanisms.

Now I know that comparing a 5W-40 modern synthetic to mineral oils isn't exactly apples to apples, and that the first number is only relevant at startup before the engine is warmed up.

But it still seems to be that such a broad viscosity spread should require a compromise somewhere else in the formulation. Could the 5W be lower than ideal on really hot days, with a starting viscosity so low that the parts aren't adequately protected? Kubota is recommending 10W as the lowest, suitable for below freezing. I'm more comfortable with 40 as the high number since that's within the multiviscosity recommendations for all temps.

Just one more new tractor owner agonizing over choices, even though all the typical options are probably more than good enough. But I want to know which one is best. By the way, I live in central Indiana, with temps from 0 - 100F, though the tractor is stored in an attached garage that never goes below 32F.

Surely everything that can be said on this subject already has, but I'm hoping someone can offer me some needed clarity on which specific synthetic I should buy, and what tradeoffs there might be in going with a broad viscosity range.

Jack
 

rjcorazza

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Equipment
L4060 HSTC Loader, ZD326, ZD1211
Mar 9, 2016
778
22
18
Hyattstown, MD
I decided on 5w40 for my new tractor. Back in the late 70's a large number spread (10w40) caused oil related problems, but not so with today's oils.

"Could the 5W be lower than ideal on really hot days, with a starting viscosity so low that the parts aren't adequately protected?"
The (W)inter number is a empirical number that has no direct relation to the second number in an oil viscosity spec. A lower "W" number only means that the oil in question thickens less at cold temps.
If you want a good read on everything oil related check out bobistheoilguy web site.
 

1970cs

New member
Apr 26, 2016
1,124
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0
Grand Ledge
As a dealer, I always recommend Kubota filters and oil. But you can use any diesel grade 10W-30 or 15W-40 oil of your choice.

I would highly suggest not using a synthetic oil until you have a few hundred hours to properly seat rings and basically break it in.

Pat
 

mudog88

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1982 B7100HST-DT, RC60-71H MMM, 5ft. back blade
Aug 11, 2015
98
1
8
Pine Village, Indiana
I decided on 5w40 for my new tractor. Back in the late 70's a large number spread (10w40) caused oil related problems, but not so with today's oils.
If it helps much, I use the Amsoil 15W-40 heavy duty diesel oil all year long. I'm in central IN too, so the temps are fairly similar. Still depends on what county you're in, but you already know what I'm talking about there. :p
I've never had any issues in the winter, still spins over nicely without the decompression pulled. Granted, my engine has 2700 hrs on it, so it's well broken in. I've got roughly 25 hours on my current oil change and it's only just starting to get a bit dark, if that tells you anything about the quality of oil.
I also agree with 1970cs on the break-in deal. But in all honesty, were I in your shoes, I would do what feels right, as long as it doesn't harm any warranties. :)
 

ironpony

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Equipment
B7100
Mar 4, 2016
84
0
6
Lancaster Ohio
I run Valvoline Super Blue in all my diesel stuff, recommended by Cummins is good enough for me. I think it is 15w-40, I am not where I can check right now.

Break in on new engines is not as critical as it used to be, do to the modern machining tolerances. New vehicles come with synthetic from the factory.
 

85Hokie

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Jul 13, 2013
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As a dealer, I always recommend Kubota filters and oil. But you can use any diesel grade 10W-30 or 15W-40 oil of your choice.

I would highly suggest not using a synthetic oil until you have a few hundred hours to properly seat rings and basically break it in.

Pat
Oil.......

mmmmm.......

aint got the time to go into it now:D:)

Let's take this one step at a time -

"But I've long been a Mobile 1 user in my vehicles"

I HAVE TOO - 30 + years!

"Now I know that comparing a 5W-40 modern synthetic to mineral oils isn't exactly apples to apples" TRUE STATEMENT

"Could the 5W be lower than ideal on really hot days" NOPE - going to be fine!

"But it still seems to be that such a broad viscosity spread"
NOT TRUE - in the statement as stated

"By the way, I live in central Indiana, with temps from 0 - 100F, though the tractor is stored in an attached garage that never goes below 32F" IF TRUE - you should never need the 5 ! :D:)

"I would highly suggest not using a synthetic oil until you have a few hundred hours to properly seat rings and basically break it in." FALSE - ZERO basis for this and simply NOT TRUE.

When you look at the first number pure and simple, you are looking at the viscosity of the oil ....cold, I think everyone gets that.....the larger number is a number that the oil "behaves like" when working.

more and MORE car companies ( and I get it - this aint about cars) are moving the first number down.....and the second number down too!!!!! Read up - Ford and GM and other foreign makers are starting to place 0W-20 and the like in their new cars.....and SYNTHETIC from the first turn of the key!!!!!!!!!!!!!

and I understand this statement 100%
"I'm willing to pay more just for the peace of mind that I didn't try to cut any corners in keeping my engine well lubricated."

But - you need to find this "formula" in the diesel type that can be obtained "EASILY" without breaking the bank!

OILs are STILL getting better all the time - you can get 0w-20 at wally-world in Mobile 1 .........but I do not see it in DIESEL format!

Last statement -

DIESELS abuse oil worse that gassers, it needs a little more "stuff" in the oil to make it work better over time, but the FIRST number is the same and the LAST numbers means the same too as oil for gas cars - DIESEL have more additives in it also,

personally I would buy 5w-40 and smile like hell - you engine will love you too!:D:)
 
Last edited:

LDowney

Member

Equipment
Kubota MX6000
So what is the consensus? Is using the Rotella T6 5W-40 acceptable oil for the Kubota? I'm coming up on my 50 hr service as well and was planning on using the T6 oil along with the appropriate filters from my local Kubota dealer.

How many recommend using the T6 in these engines?
 

mudog88

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Lifetime Member

Equipment
1982 B7100HST-DT, RC60-71H MMM, 5ft. back blade
Aug 11, 2015
98
1
8
Pine Village, Indiana
So what is the consensus? Is using the Rotella T6 5W-40 acceptable oil for the Kubota? I'm coming up on my 50 hr service as well and was planning on using the T6 oil along with the appropriate filters from my local Kubota dealer.

How many recommend using the T6 in these engines?
What I got from Hokie's post was that it's just fine. I would personally stick with a 15w-40, but it depends on what environment you're using it in. Your owners manual will tell you what oil to use for your particular environment. But from what I've heard, the T6 is a great oil. I have no personal experience with it. All my engines run Amsoil. I'd follow your manual, change the oil, start it up, and smile! :cool:
 

85Hokie

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Last edited:

LDowney

Member

Equipment
Kubota MX6000
I would and will ! Rotella T6 5W-40

at this cost......I would consider this cheap!

http://www.walmart.com/ip/14958681?...39599072&wl4=&wl5=pla&wl6=52987236566&veh=sem

and even at this :

http://www.walmart.com/ip/Shell-Rot...tor-Oil-1-Gallon-Casepack-of-3-units/42299972

thats $18.33 a gallon !
Yeah, I saw that as well. $19.16 per gallon. Plan on picking up several my next trip to Walmart.

Well, I just wanted to make sure I wasn't the lone wolf with this oil. I'm glad the OP started this thread. Saved me the trouble. I was just wondering this the other day. Thanks guys for the feedback.
 

ironpony

Member

Equipment
B7100
Mar 4, 2016
84
0
6
Lancaster Ohio
Just an FYI if you guys have never run it, it has a unique odor to it, from the crank case breather. Might not be as noticeable on a tractor but that is the only complaint from diesel truck owners. Smells in the cab, thats why I stopped using it in my truck.
 

1970cs

New member
Apr 26, 2016
1,124
3
0
Grand Ledge
Oil.......

mmmmm.......

aint got the time to go into it now:D:)

Let's take this one step at a time -

"But I've long been a Mobile 1 user in my vehicles"

I HAVE TOO - 30 + years!

"Now I know that comparing a 5W-40 modern synthetic to mineral oils isn't exactly apples to apples" TRUE STATEMENT

"Could the 5W be lower than ideal on really hot days" NOPE - going to be fine!

"But it still seems to be that such a broad viscosity spread"
NOT TRUE - in the statement as stated

"By the way, I live in central Indiana, with temps from 0 - 100F, though the tractor is stored in an attached garage that never goes below 32F" IF TRUE - you should never need the 5 ! :D:)

"I would highly suggest not using a synthetic oil until you have a few hundred hours to properly seat rings and basically break it in." FALSE - ZERO basis for this and simply NOT TRUE.

When you look at the first number pure and simple, you are looking at the viscosity of the oil ....cold, I think everyone gets that.....the larger number is a number that the oil "behaves like" when working.

more and MORE car companies ( and I get it - this aint about cars) are moving the first number down.....and the second number down too!!!!! Read up - Ford and GM and other foreign makers are starting to place 0W-20 and the like in their new cars.....and SYNTHETIC from the first turn of the key!!!!!!!!!!!!!

and I understand this statement 100%
"I'm willing to pay more just for the peace of mind that I didn't try to cut any corners in keeping my engine well lubricated."

But - you need to find this "formula" in the diesel type that can be obtained "EASILY" without breaking the bank!

OILs are STILL getting better all the time - you can get 0w-20 at wally-world in Mobile 1 .........but I do not see it in DIESEL format!

Last statement -

DIESELS abuse oil worse that gassers, it needs a little more "stuff" in the oil to make it work better over time, but the FIRST number is the same and the LAST numbers means the same too as oil for gas cars - DIESEL have more additives in it also,

personally I would buy 5w-40 and smile like hell - you engine will love you too!:D:)
I would agree to the automakers using blends or full syn. due to tighter tolerances in bearing clearance. So it is easier to build (the wedge) between surfaces. Heck I have GM cars and we use blends or full synthetics unless they are 2011 and before. My dad had 325,000 miles on his caprice and only used conventional oil and the engine was never touched internally!

Agreed diesels will have more carbon particles. So the oils have better suspension properties. Gas burners will dilute the oil and that's why you about detergents.

But per Kubota recommendations to use certain weights per climate. They do not specify synthetics, unless we are talking super udt trans/hydraulic oil.
 

Ramos

New member

Equipment
1870-1, LA203A, RCK54
Feb 25, 2016
463
3
0
Sherman County, Oregon
85Hokie, please do expand upon your thoughts in regards to synthetics in new(er) engines.

My Kubota dealer ('16 BX1870-1) says not to use synthetic engine oil until after 200 hours.

My Dodge dealer ('12 Cummins) says not to use synthetic engine oil until 20,000 miles.

My Jeep dealer ('16 Cherokee gasser) says not to use synthetic engine oil until 20,00-30,000 miles.

All, regardless of the factory oil. Initial changes are at 50 hours (BX) and no more than 3,000 miles for the vehicles.

Also, I know John Deere ships their rowcrop and bigger tractors with a reduced lubricity break-in oil in the crankcase.
 

Mike9

Active member

Equipment
Kubota B6200
Oct 9, 2015
391
31
28
Ghent, NY
Ya know - my B6200 manual calls for 15W-40 so that's what I use. What does your manual recommend?
 

85Hokie

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Bedford - VA
85Hokie, please do expand upon your thoughts in regards to synthetics in new(er) engines.

My Kubota dealer ('16 BX1870-1) says not to use synthetic engine oil until after 200 hours.

My Dodge dealer ('12 Cummins) says not to use synthetic engine oil until 20,000 miles.

My Jeep dealer ('16 Cherokee gasser) says not to use synthetic engine oil until 20,00-30,000 miles.

All, regardless of the factory oil. Initial changes are at 50 hours (BX) and no more than 3,000 miles for the vehicles.

Also, I know John Deere ships their rowcrop and bigger tractors with a reduced lubricity break-in oil in the crankcase.

Ok,

lets start here :

http://www.streetdirectory.com/trav...should_i_use_synthetic_oil_in_my_new_car.html

and here :

https://mobiloil.com/en/article/car...r-oil-facts/synthetic-oil-vs-conventional-oil

more :

http://www.pennzoil.com/en_us/educa...-oil.html#iframe-L2JyYW5kcy9wZW5uem9pbC8wMQ==

and still more:

http://www.upmpg.com/benefits.htm

and lastly.....

https://mobiloil.com/en/article/why...car-manufacturers-recommend-mobil-1-motor-oil

Let us clear up something......and we all have common sense......now dont we?;):rolleyes:

your grandmother told you NOT to go outside under-dressed or you would catch a cold....

horsesh!t....not true.....


you cannot go swimming right after eating, you will cramp up ....

horsesh!t....not true.....

Dropping a penny from a tall building will kill someone.

horsesh!t ....not true

Cracking your knuckles gives you arthritis.

horsesh!t..... not true


You can see the Great Wall of China from space.

wrong.....sorry china


Antibiotics kill viruses.

again......bullsh!t

and one of my favorites:

It takes seven years to digest swallowed chewing gum.

holy batsh!t batman....this one is got to be true.....

nope......



so - let me say this....

synthetic is slicker than conv oil.....

WRONG

synthetic will leak around seals.....

WRONG (if bad - gonna leak anyway)

Synthetic is .....more 4x more expensive than conv oil.....

WRONG......

what do all these DEALERS have you believe ?????? DID they show you in PRINT,
DO NOT use synthetic oil in this .......machine??????

well? please post the print FROM that manufacturer that says.....

NO SYNTHETICs for this machine until ..........whatever.......


and some of us believe that Jesus was really born on Dec 25......please dont make me go there.......

and still many believe that if you dont change your oil at 3000 miles....parts will fall off.......

Anyone have a Honda???? 7500 is their mileage......ever seen a Honda go for 250,000 miles.....nuff said.


Here is what I would do ------ follow you dealers word to the letter......

BECAUSE THAT GUY IS NOT AN ENGINEER - NOR A PERSON THAT WOULD KNOW SYNTHETIC OIL FROM A JAR OF MELTED VASELINE.......THAT GUY (SORRY LADIES) IS A S A L E S M A N REPEAT ---- HE SELLS STUFF, PERIOD - END OF DISCUSSION........




but .....those who have an open mind......

cut and pasted :

In a nutshell, synthetic oil is thinner, resists temperature extremes better and generally lasts longer. You likely won’t notice any difference in how your car performs, but the durability characteristic is the most important from a car owner’s perspective, as it translates to less frequent oil changes compared to conventional motor oil.

“The fundamental difference is that synthetic oil can go longer before it starts to break down when compared to conventional oil,”

Although recommended oil change intervals vary by vehicle manufacturer, in general, a good rule of thumb to follow is to change conventional motor oil every 3,000 to 5,000 miles.

“If you’re using full synthetic oil, we recommend going about 7,500 between changes,”

......... synthetic oil and some manufacturers, intervals between oil changes can be much, much longer: "In some cases as much as 15,000 miles or one year."


now - Ramos - Am I pissed? no, not at all - you have a legit question - and I understand your question.......

But .....with opinion, that has to be some kinda facts........AND WITHOUT F A C T S ......IT IS AN OPINION.......

And - to each their own.
 

D2Cat

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L305DT, B7100HST, TG1860, TG1860D, L4240
Mar 27, 2014
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40 miles south of Kansas City
85Hokie, I got a question. If I'm in the freezing weather in Minnesota in the winter and I put my tongue on a guy-wire that been in this cold, will my tongue get stuck on the metal?

Is this BS to?:D:D If it is, I should have tried it!
 

85Hokie

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85Hokie, I got a question. If I'm in the freezing weather in Minnesota in the winter and I put my tongue on a guy-wire that been in this cold, will my tongue get stuck on the metal?

Is this BS to?:D:D If it is, I should have tried it!
tell you what - let me have 30 minutes to draw a crowd ....and you can test that !:D:)

https://www.youtube.com/watch?v=NigyrT7nLBQ
 

lucweg

New member

Equipment
L1-24 Sunshine, rototiller RL1401 (?), plow, cultivator, flail cutter
Aug 27, 2013
23
0
1
70
Belgium
Hello,

I am living in Belgium which has a moderate climate.
I am using the Shell Rimula R4 15w-40 on my L2201DT and everything is going fine with it, even in the winter.

Lucweg