What temperature is too hot for conventional oil?

[CarbonSteel]

Originally Posted By: userfriendly
http://lubes.exxonmobil.com/basestocks/products.aspx
I am not sure what you are trying to convey.

 

[CarbonSteel]

Originally Posted By: mbacfp
2015_PSD, have you noticed any difference in regen frequency between those oils? Thanks.
No difference between the oils, but I have seen increased mileage between regens by using Stanadyne (both Performance and Lubricity formulas) and I also have a sample of Archoil to try in the near future. I did see the longest mileage between regens on this trip (620 miles) and I averaged 19.1 (including regens).

 

[mbacfp]

Thanks 2015_PSD. Been using archoil 6200 and it seems to be good stuff. My truck regens every 500 miles irrespective of gpl. Programming on the cab & chassis might be different than on the pickup trucks. Appreciate the info as always.

 

[userfriendly]

2015_PSD;
The question is; "What temperature is too hot for conventional oil?"
Other than comparing the flash points of one "finished" product to the next,
how can that question be answered?
Instead of guessing attributes of various base oil group types,
I provided the links to a few of the major base oil manufactures.
Eliminate 5W and 0W prefix grades from your selection for extreme heat resistance.
You don't need either of those winter grades nine months of the year.
That leaves 10W40, 15W40 and SAE40 for your extreme heat XXW40 selection.
I left 10W40 in the group, because that is a grade often overlooked in North America.

 

[CarbonSteel]

Originally Posted By: userfriendly
2015_PSD;
The question is; "What temperature is too hot for conventional oil?"
Other than comparing the flash points of one "finished" product to the next,
how can that question be answered?
Instead of guessing attributes of various base oil group types,
I provided the links to a few of the major base oil manufactures.
Eliminate 5W and 0W prefix grades from your selection for extreme heat resistance.
You don't need either of those winter grades nine months of the year.
That leaves 10W40, 15W40 and SAE40 for your extreme heat XXW40 selection.
I left 10W40 in the group, because that is a grade often overlooked in North America.
OK, that helps clarify. In my area, there are only two "40" grades from which to choose: 5W-40 and 15W-40. I like Kendall 15W-40 (SynBlend), but Chevron Delo 400 LE 5W-40 is only $1 more per gallon, so for me, it will probably be one of those two for the long haul. Both 0W and 5W are still 40 (generally speaking) so why would one exclude them?

 

[userfriendly]

http://lubricants.petro-canada.ca/pdf/petro-Canada_lubricants_2016_handbook_english.pdf

Pet-Can (Suncor), publishes HTHS and flash points on many of their products.
You will notice as a group, 0W30, 0W40 and 5W40 have lower flash points and HTHS
for their respective KV100C viscosity, than tighter grade 10W30, 10W40, 15W40 and mono-grades.

You pay for 5w40 with less HTHS and a lower flash point than 15w40.
HTHS viscosity is what your plain bearings see in worst case scenario.
Duron mono-grade HTHS: #30 >3.5 #40 >4.3 #50 >5.3

 

[Garak]

Originally Posted By: 2015_PSD
Most of the synthetic oils (HDEO and PCMO--perhaps except for Chevron) are Group III and some Group IV are they not?

The Delvac 1 ESP 5w-40 is primarily Group IV. I wouldn't worry about its ability to handle the heat in the least, or that it's a 5w-40 versus a 15w-40. Synthetic 15w-40 options are available, but not all that readily and not that cheaply. RP 15w-40 does come to mind.

 

[userfriendly]

The question is; "What temperature is too hot for conventional oil?"
The original post'er (OP) lives in Texas, and is concerned that conventional can't handle the summer heat.

I don't like using me, myself and I.
The question was not what I would do, but with the two choices given,
I would go with 15W40 "conventional" instead of 5W40 "synthetic".

 

[Garak]

Ahh, I see your point. I mentioned earlier, too, I wouldn't worry too much about a conventional there, either. It meets the specifications. Of course there are exceptions, but one would hope the OEM has an idea of what they're doing when they made their specification in the first place.

 

[Shannow]

Originally Posted By: userfriendly
I don't like using me, myself and I.
The question was not what I would do, but with the two choices given,
I would go with 15W40 "conventional" instead of 5W40 "synthetic".



There's a school of thought that synthetic, with it's high VI, will have a flatter viscosity curve, and "protect" more at higher temperatures...big end is considerably hotter than the bulk oil temperature.

So a 5W40 synthetic SHOULD be better than a 15W40 with it's higher slope, shouldn't it ?

I think you are hinting that the 5W40 synth would have an HTHS of 3.8 typically, while the 15W40 is likely around the 4.4 range.

So regardless of the synthetic having a higher VI, and clearly better KV150, the 15W40 will do better at protecting the big ends.

As to what's too hot ?

oxidation resistance needs oxygen, and most of the crankcase ventilation systems I'm familiar with these days don't go sending fresh air in to wash through the flying hot oil like they did in the early days...yes blowby gasses are harsh also.

 

[CarbonSteel]

Originally Posted By: Garak
Ahh, I see your point. I mentioned earlier, too, I wouldn't worry too much about a conventional there, either. It meets the specifications. Of course there are exceptions, but one would hope the OEM has an idea of what they're doing when they made their specification in the first place.
Yes, which is why I questioned using a conventional in an earlier post when Ford specifies 5W-40 for towing, high heat, use of biodiesel, etc. The summer heat is not my concern, it was seeing 240F oil temperatures for extended times. While I could be wrong, it just does not seem plausible that a conventional would withstand more heat before breaking down versus a synthetic.

 

[Garak]

That's a very good question. That's why it would be nice if Doug wandered through here. At least from what I recall of his posts over the years, he certainly has confidence in synthetics in high temperatures. Given his experiences and climate, I would suggest his position to be extremely well reasoned.

Now, you have me thinking. I wonder how peak oil temperatures compare in your current Powerstroke versus something like a 7.3, for example, from around twenty years ago. Geeze, it's been that long already?

 

[roadrunner1]

Ford doesn't spec a 15w-40 simply for economy reasons, even though the F250's up aren't CAFE required. Synthetic isn't in the equation even though that is the only way to make a 5w-40 meet spec.

The 6.7 has a thermostatically controlled oil cooler circuit, which is fully open at 245F, if one was constantly at the 245F threshold, then yes a 40 wt. would handle the constant high temp within the engine. Notice the omission of synthetic as CJ-4 spec is required to handle the higher temps of modern diesel engines. My personal experience with 5w-40 (CI-4+) was that it didn't hold up nearly as well as non-synthetic 10w-30 & 15w-40 through UOA data.

One can spend more money thinking he getting a better product, get some UOA data for your truck/usage and let the data tell you what is working.

 

[mbacfp]

Thanks Roadrunner...now I am confused. So delvac 5w40 with its higher flashpoint doesn't necessarily mean superior durability while under extreme temperatures vs non synthetic 10w-30, 15w-40? Still learning...so I apologize if I am missing something. Great stuff.

 

[roadrunner1]

Originally Posted By: mbacfp
Thanks Roadrunner...now I am confused. So delvac 5w40 with its higher flashpoint doesn't necessarily mean superior durability while under extreme temperatures vs non synthetic 10w-30, 15w-40? Still learning...so I apologize if I am missing something. Great stuff.


If you're never reaching the flash point in your usage, then no. Everyones duty cycle is different and one needs to make a selection accordingly. For my trucks use 10w-30 seems to cover everything I do or am going to do, I have proven this to myself through UOA. I let the IOLM go to 0%, sample and change. The main reason for UOA now is to check for any fuel contamination, which I have never had. My samples have always came back stellar and state that I could go longer, I had one that was 10,000 mi. OC and could have extended. I am satisfied following the IOLM.

 

[TiredTrucker]

As a reference, Detroit has recommended OCI on their 13L and 15L platforms of 50,000 miles on conventional 10w30 CJ-4. Now true, the capacities are larger, but so is the engine by a considerable amount. And their recommendation covers from the Mexico to Canada, coast to coast, with truck and cargo weights up to 80,000 lb.

 

[CarbonSteel]

Originally Posted By: roadrunner1
Ford doesn't spec a 15w-40 simply for economy reasons...
They also do not specify 15W-40 for any of the conditions I experienced recently. In fact, for anything other than normal use they state 5W-40. Why is that if 15W-40 or 10W-30 is more appropriate?

 

[roadrunner1]

They dont spec 15w-40 in the 6.7 period, manufacturers are moving away from 15w-40 for economy reasons. Your original question was" what temp is too hot for conventional", you haven't even come within 150f of the flash point.

I never said one was more appropriate than the other, I did say that a conventional will work just fine as the 6.7 is thermostatically controlled for the oil temp and your truck is functioning as it was designed. As I stated earlier CJ-4 spec is designed for the higher temps currently encountered in modern diesels, so conventional or synthetic has to meet the same spec. UOA and see for yourself as only you can determine what oil to put into your fill hole.

I have a Deere 6076 (7.6L) in a marine application that gets run at governed speed for hours on end with oil temp 240F on 15w-40 and at 500 hours oil samples come back "OK for extended use"(500 hrs. is manufacturers suggested OCI).

I have never read or heard of one single 6.7 failure because the owner ran conventional CJ-4, whatever grade. There are literally millions of trucks, heavy equipment,farm equipment, and marine engines running conventional and not seeing equipment failures because they're not using synthetic oil. The CJ-4 spec is not an easy spec to meet and with CK-4 rolling out this fall it will be even tougher to comply with.

 

[mbacfp]

Does it really come down to the fact that the performance/quality gap between conventional and synthetic motor oil has narrowed substantially? In Ford’s case (regarding the powerstroke 6.7), their OCIs (oil minder) will have you change the oil long before any catastrophic oil breakdown? Their thermostatically controlled oil temp parameters ensure that?

In the case of severe service recommendations, Ford has no idea on temperature climate environments, etc...thus recommending the broadest (5w-40) oil for everyone in those unknown circumstances?

The real question (granted unrealistic) is what oil would you want in the crank if you had to endure 240 degree oil temps for the entire OCI? Would synthetic do better in that extreme case?

 

[edyvw]

Originally Posted By: mbacfp
Thanks Roadrunner...now I am confused. So delvac 5w40 with its higher flashpoint doesn't necessarily mean superior durability while under extreme temperatures vs non synthetic 10w-30, 15w-40? Still learning...so I apologize if I am missing something. Great stuff.

Nope it does not mean superior durability, but it has one. Many conventional oils have same flash point as synthetic oils. However, that does not mean anything. Synthetic oil molecules are going to breakdown much slower. Better base oil will provide better HTHS and heat exchange with surrounding air. Just because both synthetic oil and conventional oil are W40, doe not mean HTHS is the same, and that is key number in turbo applications. Also, more PAO and especially ester in base will provide faster heat exchange.
IMO, does not matter application (except my Honda power washer) ALWAYS synthetic oil.