15w 40 to thick?

[Garak]

Originally Posted By: dnewton3
While I like to recommend dino 10w-30, it's not often easily found for all. JD has an excellent 10w-30 dino; roadrunner1 has many a testament for it's effectiveness.

This exactly. It's readily found on JD's shelves up here and is appropriately marked with the diesel specification.

 

[jim78]

I have not used those kinds of oils before nor do I know anybody who has they just sound good to me just wanted to get some info first before I used them.

 

[skully]

this is the first in many years that my jd excavators and backhoes are filled with t6 rotella. equipment when onsite is not plugged in and in this winters cold this is the lightest and best for starting/operating in these temps. if this unit has a block heater and its used, you will be fine but dropping down to jd winter oil or a slighlty lower viscosity diesel oil wouldnt hurt either.

 

[Black_Thunder]

I have a NH TC30 with a 3 cylinder diesel. right on the hood or engine somewhere there's a sticker that suggests what oil to run with different temperatures etc.


I've been running Rotella 10w30 in mine, and the last time i changed the oil i put T5 in it.

I've thought about running 5w40 in it as well but so far 10w30 year rounds seems fine.

 

[IndyIan]

Rotella T6 5W40 and Rotella T5 10W30 are actually pretty close in terms of cold flow.
I decided to just stick with 15W40 this winter as usually it only snows near freezing, but this winter has been an exception. I still only start above -10C and the tractor has no problems at all. I have started it in -20C with 5W40 in past winters but I won't do that with 15W40 unless its some sort of emergency.
Next change I'm going back to 5W40 and not worrying about cold or hot temperatures!

 

[jim78]

Went ahead and switched to 5w 40 a week ago and man what a difference it starts a lot easier and runs a lot smoother at the beginning. Used the moble 1. Full synthetic heavy duty diesel oil. Drained that 15 40 out at 30 degrees. That stuff barely came out glad I got it out. Just think, that stuff was trying to pump through the engine at 0 degress.

 

[dnewton3]

Gravity flow and pumping resistance are two totally different concepts; that's why they have different ratings. Most folks just don't get that.

T5 will do anything T6 can do, for less cost, in 99.9999999% of applications.

 

[marco246]

jim78,

I have a couple of JD compact tractors with Yanmar engines. The bigger one (4610) requires 15W-40 or SAE 30 for my climactic conditions. It gets the former. The smaller tractor (2305) requires 5W-30 or 10W-30 and gets the latter. All recommendations are for HDEOs, of course.

You can't go far wrong in following the guidance in the owner's manual and using 10W-30--if you can find it.

 

[jim78]

Yes different concept definitely but it's a 3/4 inch hole vs 1/16 and if it can't travel through that hole very well guess where it's going. Out the relief on the oil pump.

 

[dnewton3]

The excess pressure goes out when the pump relief opens, not all pressure. The engine oil circuits will still have pressure even when the relief burps open. The relief at the pump is to protect the filter and the pump itself from being overly stressed. But it does not dump 100% pressure away from the engine; it only dumps pressure in excess of it's setting as it cracks open the valve against the spring. If your pump developed 150 psi, and your BP setting was 90 psi, only the excess 60 psi would vent. The numbers will fluctuate a bit because springs are great at their job, but they are mechancial devices and subject to the priciple of mass reaction, etc. But the key to this concept is that the relief only vents the excess, not all. Again - many folks don't understand how the lube systems work ...

Your tractor presumably has a little Yanmar engine; one of the great small diesel companies out there. Frankly, it's not going to matter to the engine one little bit if you choose a 5w-40 or 10w-30; you'll NEVER, EVER see any practical wear difference between the two. I presume this engine to be an IDI with traditional fuel pump; there is no common rail injection nor intake grid heater. The only two starting aids you have are the speed of compression (diesel cycle principle) and the glow plugs; a good, strong battery is going to help there. When viewing the cc simulator ratings for T5 10w-30 and T6 5w-40, they are essentially the same. You will not see any practical difference, in IL, in cranking speed between those two choices, or similar options. I know; I've experimented with each and I could not tell any difference whatsoever.

5w-40 is not going to be one sliver of a fraction of a percent "better" for your engine over a decent 10w-30. But, I suspect it will be "better" for your mind, if that's what you want to believe. After all, it's your tractor and you should treat it as you see fit. And so, after careful consideration, I am going to revise my suggestion for you:
You should use only top-tier synthetic 5w-40 boutique lubes, add bypass filtration, change the lube every weekend and filters once a month. You know; 'cause it's "better".

 

[Shannow]

dnewton3, re your first paragraph, I get where you are coming from, but, not quite with your analogy.

If the system provided 150psi, but the relief was 90, it's like opening the faucet in the kitchen and the laundry, using the laundry to control the pressure/flow in the kitchen.

Said spring is the controlling element, and while ever the pressure in the kitchen is under 90psi, nothing happens.

Once the pressure gets above 90psi, the flow to the laundry increases to keep the kitchen pressure a constant...or near-so...kitchen sink doesn't suddenly starve because Jeeves, the attendant in the laundry opens his faucet.

BITOG at the moment seems to have the belief that if the pump relief opens, the engine starves.

 

[dnewton3]

I would agree that the math is not exact, which is why I stated the spring is subject to mass mechanical equations.


Much of this depends upon the total available volume versus total consumed.

In the engine example, the oil circuits will see a small pressure drop versus where the "normal" pressure would be, but it would likely be less than 10% in estimation.

In your household example, if the pump can supply 70 psi to the whole home and at a rate of 10gpm, and you open a 2gpm faucet to relieve the system, it's not like the entire house will see pressure at every other faucet drop to zero. As you open each faucet, some amount of pressure decay will exist with each opening event. Each faucet may bleed off 5 psi. 70 psi available minus one = 65 psi. Open another and you'll get 60 psi, etc, etc. I see this every day with my well pump.

In the engine, if your pump relief is set at 90 psi, and the pump itself is providing 150 psi, you'll still get the vast majority of that 90 psi into the engine. It might drop a bit to 85"ish" psi, but it's not like the engine will starve! And there is only one planned escape for the oil; the relief. It's not like there are multiple reliefs in an engine pump system; just one exists, so you'll not see a "stacking" effect in pressure loss.

I have personally seen two oil filters (rated around 300 psi) burst on a truck. That tells me that when a pressure relief is not present, a pump can reallly push the fluid! And so, if your pump relief is 90-100 psi, and the pump is capable of MUCH more than that, the delta-P drop below the setting is going to be minimal.

There is so much excess capacity for pressure in a normal positive displacement engine oil pump that the relief event will NEVER starve an engine, not even close. If the VOLUME were suspect, then you'd have to question the design of the OEM system. Typically, I do not see either pressure OR volume being a problem in modern engines. The lube system can supply WAY MORE than the engine needs, even during relief.

I was being simple for the example. I think we agree on the concept, but I was overly simplistic in my first example. I hope this clears it up.

 

[Shannow]

:meh: delete my last post...I give up

 

[dnewton3]

This same concept applies in eletronics as well ...


If you have plenty of voltage and amperage available, then turning on "more" lights does not drop the entire system to zero.

Provide 110v with large amp capacity, and turn on a light. You get light. Turn on another light, and the voltage will drop a tiny bit, and the amperage will respond presuming it's already over capacitized. Keep turning on lights and you get continued volt drops with amp comsumption. See enough come on and you may even be able to distinguish a perceptive light loss at visual level. In our homes, there is enough system capacity to simply pump the volts back up to normal. But if you did this with a generator and ran near full capacity, you can actually see volts drop with reduced lighting energy perceived in the room.

However, it's not like turning on one light steals the potential power from all other sources ....


Bottom line is this: the engine pump relief will NOT starve an engine of oil in a properly designed and operating system; they are typically designed to supply both pressure and volume well above the need of the actual oil circuit, period. Which means his objection was based on his flawed understading of how the system works.

 

[fpracha]

Originally Posted By: dnewton3
There is so much excess capacity for pressure in a normal positive displacement engine oil pump that the relief event will NEVER starve an engine, not even close. If the VOLUME were suspect, then you'd have to question the design of the OEM system. Typically, I do not see either pressure OR volume being a problem in modern engines. The lube system can supply WAY MORE than the engine needs, even during relief.

I was being simple for the example. I think we agree on the concept, but I was overly simplistic in my first example. I hope this clears it up.

Dave, yes you are right. I fully agree with your concept of VOLUME flow versus PSI pressure ratings and the fact that engine oil pump has a MASSIVE supply ability more than normal needs of each engine.

Following from this concept, I have been trying to understand the difference in flow between 0w-20, 5w-20, and a 0w-30 grade and its resulting "fuel economy variances, if any" in today's modern gasoline and diesel engines.

So is it safe to say that a 0w-20 flows better than a 5w-20 and a 0w-30, and therefore provides better wear protection ?

Is it really true that a 0w20 (like the high VI TGMO or Sustina) will actually give a noticeable fuel saving when compared to a 5w-20 grade and a 0w-30 grade oil ?

I hope my questions are clearly worded. Otherwise please ask for my further clarification.

Hope to see your replies.

 

[dnewton3]

At cold temps, the 0w-20 will certainly flow "better" than the 5w or a 10w. I don't know that it would be appreciably "better" than a 0w-30 versus the 0w-20.

At operating temps, they will all have the viscosity relative to their grade, so none would be any different than another (appreciably) in their respective grade. A 0w-20 and a 5w-20, both of similar construction, are likely to be very similar. The 30 grade would obviously be thicker. Vicosity is the resistance to flow; a higher grade will resist flow moreso than a lower one. But ...

Any of those grade will be more than adequate to protect an engine from wear, presuming they are in an appropriate application.

Looking over the data in my UOA files, I cannot find any reason to believe that minor grade shifts (i.e. 5w-30 to 5w-20) will result in any tangible difference in wear. The hydrodynamic barrier and tribochemical barrier hold wear to very low levels; the grade isn't a wide enough spread to induce statistical variance worthy of noting (it's noise).

A large disparity in grade selection (using a 15w-40 where a 0w-20 is spec'd) may result in a wear shift, but I cannot attest to the results because that kind of data is practically non-existent. I can speculate, but I cannot prove anything, because facts are absent here when it comes to macro data.


In short, I don't see data that indicates a shift in wear by the minor grade changes. What I see is that the thinner grades can "flow" easier, and that reduces parasitic drag at the pump and at the journals and cylinder walls; that in turn all adds up in CAFE ratings. The "better" flow isn't a benefit to the wear curve; it's of benefit to the economy of operation.

 

[jim78]

15w 40 to thick again I know how a oil system works I presum that you think nobody else does. Look if the oil is to thick to pump your engine is not going to get sufficient lubrication during start up, plain and simple. think about it what's the two main things on an engine that wear out first,and need lube right away, think about it.

 

[dnewton3]

Start up wear is NOT controlled by oil pressure. It is controlled by the tribochemical barrier that exists. Proven and studied at length in SAE 2007-01-4133. Buy it and read it.

I do not think that "nobody else" knows how a lube system works.
I do know that some (many) people don't truly understand the entire relationship between film barriers, wedge barriers and pressure control and how they interact to control wear, although those people think they do...


At start up, there is no pressure for a very short period of time. That time is dependent upon many factors, including viscosity, ADBV presence and viability, circuit pathway length, etc. Once pressure is established, the direct lubricated parts run on a film of hydro-dynamic wedge, but that is ONLY true of pressure-fed parts. There are also many parts that are NOT pressure-fed, such as cylinder walls and ring pack.

All parts, both pressure-fed and non-pressure-fed, ride on a film of oxidized lube called a tribo-chemical barrier. That film barrier is ALWAYS present and actually grows and thickens with age. The only time this film is undesirably altered is the front end of an OCI where the anti-agglomerate and detergent package is fresh and actually destroys that barrier, and it has to build back up again. This barrier, when present, allows wear to drop to near-zero in most wear metals, and the wear rates will actually drop significantly as the OCI matures.

So, when a very cold engine starts with very cold lube, it is true that the pressure-fed components are without the wedge for a second or two. But it is completely false to state that there is no protection; the tribo-chemical barrier is what avoids wear at start up, not the pressure. Buy and read the SAE study.

And, as discussed in previous posts, just because the oil pump may relieve, it's not an indication that the oil pathways are completely void of pressure. There is plenty of pressure available because only excess pressure is bled off, not all of it. The PRV is essentially a controlled leak; it's not a total dump of all pressure at the expense of the downstream engine.

So, it goes like this:
1) first few seconds all parts ride on the tribo-chemical film barrier
2) pressure develops; some is diverted via relief, but plenty gets to oil circuits
3) pressure-fed parts ride up above the chemical film barrier onto a wedge barrier, while non-pressure-fed parts continue to ride on the film until splash lubrication and/or airborne mist will make it's way to those parts.



Yes, sir, I've "thought about it". And I've read about it. And I've run macro data analysis all over and around it, using my database of more than 10,000 UOAs. In my studies, I've looked at engines, in all manner of applications, in all kinds of environments, with all kinds of lubes. I can say with certainty that wear control at start up is a matter of the oxidized film barrier, not pressure.


I offer these to support my position:
http://papers.sae.org/2007-01-4133/
http://www.bobistheoilguy.com/used-oil-analysis-how-to-decide-what-is-normal/
http://www.cdxetextbook.com/engines/lube/sysComp/oilpressurevalve.html


.

 

[Shannow]

Originally Posted By: dnewton3

I do know that some (many) people don't truly understand the entire relationship between film barriers, wedge barriers and pressure control and how they interact to control wear, although those people think they do...


At start up, there is no pressure for a very short period of time. That time is dependent upon many factors, including viscosity, ADBV presence and viability, circuit pathway length, etc. Once pressure is established, the direct lubricated parts run on a film of hydro-dynamic wedge, but that is ONLY true of pressure-fed parts. There are also many parts that are NOT pressure-fed, such as cylinder walls and ring pack.
.


That is not ONLY true of pressure lubricated parts.

Wherever there is oil, and relative motion, the potential exists for hydropdynamics to be extant...hydrodynamics has nothing to do with applied pressure.

A considerable part of cylinder/bore interaction and cam unloaded surfaces are genuinely hydrodynamically lubricated, in spite of not being pressurised. Lower relative speeds, and higher loads introducing mixed lubrication.

 

[dnewton3]

I mentioned it, but I think you clarified it. Note emphasis of my statment ...

Originally Posted By: dnewton3
3) pressure-fed parts ride up above the chemical film barrier onto a wedge barrier, while non-pressure-fed parts continue to ride on the film until splash lubrication and/or airborne mist will make it's way to those parts.


I will agree that you described it in better detail than I; thank you!

My point was this:
At start-up, before pressure or hydrodynamic barrier is present (regardless of manner in which oil makes it to surface), it is the tribo-chemical barrier that reduces wear.


Your point, which echos mine to greater detail, only serves to bolster my point. Thick oil isn't as dangerous as folks think when it comes to start up wear. As long as you're using a lube grade that is recommended by the OEM, it should be fine. If the pump relieves some pressure, it most certainly is not relieving all pressure; much of it is still getting to the circuit. Between the tribo-chemical barrier, the splash lube, the pressure-fed lube, it's all good.