10W30 Diesel Oil Recommendations?

[RalphVa]

Thanks, mangler. The more I learn about oil, the less I seem to know! If I go with a 40-weight, the 5W-40 Mobil Delvac 1 ESP looks good. But my owner's manual only lists 10W-30 and 15W-40. So I will look at that Amsoil you mention along with their 10W-30.

If owners manual says 10w30, 0w30 and 5w30 are acceptable. For 15w40, 0w40, 5w40 and 10w40 are also acceptable. These others are better than what is mentioned in the manual.

Ralph

 

[mangler]

If owners manual says 10w30, 0w30 and 5w30 are acceptable. For 15w40, 0w40, 5w40 and 10w40 are also acceptable. These others are better than what is mentioned in the manual.

Ralph

That's the problem, at least in my manual (Kioti CK2610, 2020) it does not list the other lower cold viscosity oils as acceptable substitutes. Options are 10W30, 10W40 or 15W40. Full stop.

The other thing to remember is their is a limit to the "magic" of multi-viscosity oil. As a rule of thumb, the largest the gap between cold and hot viscosity, the higher the compromise. It can show up with things like higher volatility/burn rate, and higher degradation over time of the viscosity improvers needed to give the base oil it's "multi-grade" status.

 

[MossyDell]

mangler, something CurleyDave posted a while back comes to mind here, and I wonder about your reaction:

"There is an answer, and it is very complicated. Way back when, from '67-'72, I was in graduate school and my thesis advisor was a rheologist (a guy who studies flow of fluids). Oil is not a simple fluid, and the viscosity enhancers they add have some very unexpected effects. One of these is called the Weisenberg effect. If you do the math, and believe me, it makes calculus look like a Sunday school picnic, there is a force which tends to center a shaft in a journal bearing caused by the viscosity enhancer. This obviously reduces wear.

"Bottom line: the wider the range of viscosity the higher this force is. Other things being equal 5W-30 is better than 10W-30.

"5W-40 would be even better than 5W-30.

"This is what I use in almost everything diesel, once the warranty has expired. Until then, I put whatever the manufacturer wants in it. After that 5W-40."

 

[mangler]

mangler, something CurleyDave posted a while back comes to mind here, and I wonder about your reaction:

"There is an answer, and it is very complicated. Way back when, from '67-'72, I was in graduate school and my thesis advisor was a rheologist (a guy who studies flow of fluids). Oil is not a simple fluid, and the viscosity enhancers they add have some very unexpected effects. One of these is called the Weisenberg effect. If you do the math, and believe me, it makes calculus look like a Sunday school picnic, there is a force which tends to center a shaft in a journal bearing caused by the viscosity enhancer. This obviously reduces wear.

"Bottom line: the wider the range of viscosity the higher this force is. Other things being equal 5W-30 is better than 10W-30.

"5W-40 would be even better than 5W-30.

"This is what I use in almost everything diesel, once the warranty has expired. Until then, I put whatever the manufacturer wants in it. After that 5W-40."

I can't comment on the centering force. That may be accurate, with NEW oil, and new viscosity enhancers. I am not a tribologist, or that versed in fluid mechanics. I do wonder how the centering force affects wear though. You get most wear at start-up, or with really dirty oil. Maybe near stalling speeds it could make a difference.

What I would really like to see is a comparison of the viscosity index of 2 different vicosity oils, after say the mid point in the service life (say 3k miles). 0W40 vs say 15W40, same manufacturer, same series. The VI of high range oils is very good out of the bottle (high VI is better, as it measures the change of viscosity with temperature, where lower is better). I am wondering if the VI or high viscosity range oil (say 0W40 as an extreme) stays as good through the service life, or if you see a degradation in viscosity that is higher that with low viscosity range oil (here we could use 15W40). Pretty sure this already exists, have just never looked for the information. I would expect more degradation with higher range oils.

All this probably doesn't matter if you are on the ball, and dump your tractor oil every 250hrs.

BTW I still feel better about running 40 weight oil at high temps. Still pains me when i almost stall the tractor pushing dirt, but it feels better having the higher film strength.

 

[RalphVa]

With fully synthetic oils, I think there are really no viscosity or VI additives. All they do is control the reactions making the branched paraffinic molecules to make the wider viscosity range possible. The oils come out additive free. That's my understanding.

The lower that 1st # is, the quicker your top end will get pressurized oil. That's a fact.

Ralph

 

[oldballs]

My owners' manuals (Kubota B2620 & B2650) for my climate, suggest Kubota 10W-30. What do you suppose the manufacturer is concerned about in their recommendation? It is not a synthetic oil and the label says it is for both gasoline and diesel engines. Maybe Kubota is only concerned with the warranty aspects and not the long term benefit of engine wear.

Cheers,
Mike

 

[WilliamBos]

My owners' manuals (Kubota B2620 & B2650) for my climate, suggest Kubota 10W-30. What do you suppose the manufacturer is concerned about in their recommendation? It is not a synthetic oil and the label says it is for both gasoline and diesel engines. Maybe Kubota is only concerned with the warranty aspects and not the long term benefit of engine wear.

Cheers,
Mike

It's a suggestion, nothing more. Run any brand of diesel rated engine oil that you want.

 

[mangler]

It's a suggestion, nothing more. Run any brand of diesel rated engine oil that you want.

My experience is most times when you buy OEM branded fluids you get to pay more for the sticker they put on someone else's product...

There are exceptions, where the OEM fluid is special, or hard to find (on purpose), eg Kubota SUDT. I guess there is the convenience of not having to think about it, but you often pay for that convenience.

 

[crazyal]

Like car engines moving to 0w20 10w30 for diesels came about in vehicles to get better fuel economy. The concept is that thinner oil when warm takes less force for the oil pump (which is powered by the engine) to move. Personally I wouldn't run a non synthetic oil nor would I use anything that wasn't 0wXX. But that's because I could start the engine in below zero weather. For those of you down south 5w or even 10w is fine. If you really want to learn about oil go to "bob's the oil guy" and read up.

As for what's in the manual I would be looking at the second half of what they recommend. If it's w30 then that's what I would stick with. Engine tolerances are based on engine oil at operating temp. Things like rod bearings. If the oil is too thin it'll flow through the gap too easily. Too thick and not enough oil will flow through them. Since the trend of lighter oils for better economy is now going strong finding a lighter weight oil isn't that hard. If w30 is what they call for but w40 is optional then I would use either. Bottom line, pick the first half based on the temperatures you will be starting the tractor in and the second half on what the manual says.

 

[bfloyd4445]

Like car engines moving to 0w20 10w30 for diesels came about in vehicles to get better fuel economy. The concept is that thinner oil when warm takes less force for the oil pump (which is powered by the engine) to move. Personally I wouldn't run a non synthetic oil nor would I use anything that wasn't 0wXX. But that's because I could start the engine in below zero weather. For those of you down south 5w or even 10w is fine. If you really want to learn about oil go to "bob's the oil guy" and read up.

As for what's in the manual I would be looking at the second half of what they recommend. If it's w30 then that's what I would stick with. Engine tolerances are based on engine oil at operating temp. Things like rod bearings. If the oil is too thin it'll flow through the gap too easily. Too thick and not enough oil will flow through them. Since the trend of lighter oils for better economy is now going strong finding a lighter weight oil isn't that hard. If w30 is what they call for but w40 is optional then I would use either. Bottom line, pick the first half based on the temperatures you will be starting the tractor in and the second half on what the manual says.

Good advice except your forgetting that synthetic oils bond to metal better and don't flow off like conventional oil. I discovered this entirely by accident. I am the 2nd owner of a Ford 2000 Diesel tractor I use synthetic oil in andabout 12 years ago I had just changed the oil and my neigbor came over to ask a question which i answered then went to work out in one of my pastures brush hogging. I noticed the oil light come on but paid little attention because i had just changed it but it bothered me after a half hour or so hoggin I disengaged the pto and drove the 1/3 mile back to my shop to see what was wrong with the oil light. This old tractor dosen't have the best gauges and i don't trust them. Well the first thing i do is look at the dip stick and much to my surprise it was dry. Then i noticed there was no drain plug in the bottom of the pan. At that point I knew what happened, the last thing i do after screwing in the plug by hand is tighten it with a wrench and because of my neighbor i missed that step so the plug must have fallen out on the bumpy road over to the pasture. I must have hogged a couple of acres and driven at lest a mile or two with NO oil in the engine. Well I figured i had just killed my old tractor but put a new plug in her filled the crancase up with amzoil marine oil and fired her up. She ran perfect no smoke and 12 years or more later still runs perfect and this ole tractor gets about 100 hours of use hoggin each year. The only way i can explain away the no damage is that the syn oil really does bond with the metal protecting and lubricating even without being renewed. Thats me on the old tractor in the pix the Colonel took in 2016.