What temperature is too hot for conventional oil?

[roadrunner1]

Originally Posted By: Doug Hillary
Hi,

Originally Posted By: Garak
I'd put it this way. Roadrunner1 certainly isn't wrong. But, the argument can be made that the synthetic would hold up for longer. Doug Hillary didn't switch to synthetics because he likes the cost of synthetic oils down under. Now, if it were the original 3,000 mile OCI on the original Powerstroke, I'd keel over after filling that with synthetic.

Garak - you are correct. It was a commercial decision based on testing Mineral, Semi-synthetic and a full synthetic. Testing was to determine the condition of the lubricant and it was conducted over many OCIs and hundreds of 000s of OTR kms
Condemnation limits were reached as follows;

Mineral lubricant = 20kkms
Semi-synth = 35kkms
Synth = 90kkms

UOAs were used over many many millions of kms to confirm OCIs based on establish lubricant condemnation limits established via the OEM and the lubricant supplier

I presented the pictures of my engine teardown results (on engine at 1.2m kms) at the BITOG Conference held in Chicago several years ago

Of course I've been involved with the UOAs for several decades and in lubricant field testing for several Oil Companies since around 1959



This is the point I have been trying to make from the beginning, show the evidence that there is a problem and go from there. This thread has been nothing but conjecture from the beginning, I am not suggesting to run a sub-par lubricant and put your equipment in danger, but analyze whats being used, UOA and let the data determine what the next step should be. Current specced lubricants are designed to handle the conditions the OP experienced, to the IOLM limit, and I have provided data to show that the IOLM has plenty of a cushion that I could extend my interval.

 

[CarbonSteel]

...

 

[CT8]

Originally Posted By: Garak
I'd put it this way. Roadrunner1 certainly isn't wrong. But, the argument can be made that the synthetic would hold up for longer. Doug Hillary didn't switch to synthetics because he likes the cost of synthetic oils down under. Now, if it were the original 3,000 mile OCI on the original Powerstroke, I'd keel over after filling that with synthetic.

I am sure that Doug didn't just look at the wall and say 90,000 is a good number and that was that. The same thing with the Superduty. I know with my wifes 2002 Superduty that unless something goes wrong with something I can easily go 6,000 mile oil change intervals or 1 year with any of the oils I have run [Delo, Mobil 1300 or Rotella ] with the use my wife puts the truck through. It is not worth it to me to do analysis to milk the most use from the oil because $30.00 is half the cost of the oil change.

 

[Doug Hillary]

Hi,
CT8 - no wall looking...! The figures I quoted above are averages. We never exceeded the figures above for the mineral & semi-synth lubricants

After installing centrifuge we achieved OCIs up around 130kkms with the synthetic lubricant. For operational programming I kept the OCIs at 90kkms for all vehicles. The determining factors were always based on condemnation levels of 150ppm Fe, TAN 8, and Soot around 3 to 3.5

The synthetic lubricant also handled soot levels much better resulting in a more stable viscosity throughout the OCI - aided in the end by the centrifuge and SS 40m cleanable FF filters

 

[Shannow]

Looking at it from a different perspective, I was evaluating this sort of stuff in a past life...

http://www.power-eng.com/articles/print/...hetic-oils.html

The title of the thread is how hot is too hot ?

More pertinent is for a given temperature profile, how long is too long...

The GrIII oils had a seriously longer maintenance life than the 1s...(the 2s caused me grief, but that's another story).

Rule of thumb is that 10C increase in operating temperatures halves oxidation life (within reason).

So a synthetic could (turbine oil example)
* last 3 times as long in the same level of service/temperature; or
* handle 15C higher temperatures for the same service life; or
* some percentage of both.

 

[Garak]

Originally Posted By: CT8
I am sure that Doug didn't just look at the wall and say 90,000 is a good number and that was that.

Of course not. I don't think anyone suggested that he did.

 

[Pontual]

Gas Turbine engines don't use film of oil to separate bearing parts from main axle journals, but compressed air. So the bigger player in its oil is temperature stress, not load carrying capability. That's why they're thinner than ATF.

 

[Shannow]

Originally Posted By: Pontual
Gas Turbine engines don't use film of oil to separate bearing parts from main axle journals, but compressed air. So the bigger player in its oil is temperature stress, not load carrying capability. That's why they're thinner than ATF.


Ya reckon ?

Industrial gas turbines (and steam) use journal bearings.

And I'm pretty sure that aero engines still have oil lubricating the bearings...only air lubricated bearings I've seen are on tiny microturbines.

 

[Pontual]

Originally Posted By: Shannow
Originally Posted By: Pontual
Gas Turbine engines don't use film of oil to separate bearing parts from main axle journals, but compressed air. So the bigger player in its oil is temperature stress, not load carrying capability. That's why they're thinner than ATF.


Ya reckon ?

Industrial gas turbines (and steam) use journal bearings.

And I'm pretty sure that aero engines still have oil lubricating the bearings...only air lubricated bearings I've seen are on tiny microturbines.


Still have oil lubricated bearings from inlet fan to compressor stages (front to middle engine). Not to use oil in combustion chamber to turbine area shaft (rear). Metal casing and air passages gets up to 1100F, under air cooling, only compressed air can endure that. The engine is started with compressed air.

 

[Jetronic]

Originally Posted By: Shannow
Looking at it from a different perspective, I was evaluating this sort of stuff in a past life...

http://www.power-eng.com/articles/print/...hetic-oils.html

The title of the thread is how hot is too hot ?

More pertinent is for a given temperature profile, how long is too long...

The GrIII oils had a seriously longer maintenance life than the 1s...(the 2s caused me grief, but that's another story).

Rule of thumb is that 10C increase in operating temperatures halves oxidation life (within reason).

So a synthetic could (turbine oil example)
* last 3 times as long in the same level of service/temperature; or
* handle 15C higher temperatures for the same service life; or
* some percentage of both.


Any clue how PAO or esters (I know, big group) compare to the others regarding oxidation resistance?

 

[Dak27]

Originally Posted By: 2015_PSD
Originally Posted By: Dak27
I know we have run completely different vehicles in different applications, but I just ended my day in Yuma, Arizona. My truck's dash said the outside temperature reached a high of 115f driving in. I'm hauling a lighter load; 25K lbs on the bills of lading, so add in the weight of my truck and the trailer.

I'm running 15W40 conventional Delvac Super in a Detroit Series 60, and my oil temperature gauge never read above 200f.

Once again, we have completely different vehicles, motors, sump capacities, and applications, but I have zero concerns about a CJ4 conventional 15W40's performance in very hot ambient temperatures. I do however question it's ability to protect my motor during a cold startup in the dead of Winter in the Rockies, Upper Midwest, Northeast, so I switch over to semi-synthetic 10W30 before the coldest Winter months kick in. But many, many big Fleets run conventional 15W40 year round, and million mile motors are very common.

I have a really good friend who runs a repair shop in Utah that works on Ford, Dodge, and GM Diesel trucks/engines. His personal vehicle is a 7.3 Ford Turbo Diesel, he's really knowledgeable on these trucks and motors, if you'd like, I'll ask him about your initial post.
Please do; more information is always a good thing, he just has to remember the 6.7L platform has full emissions controls in place. I am certain the differences in the capacities and systems between an OTR vehicle and mine account for the differences in oil temperature.


I finally was able to chat with my friend about the operating temperatures you've seen with your 6.7. He said in those hot of ambient temperatures, it's not uncommon to see the operating temperatures your engine is showing.

I read him the responses you received from Kendall, Shell, and Mobil in regards to conventional vs synthetic oil operating in hot temperatures.

Although my friend is really Old School in regards to the "Thicker oil is Better" philosophy, and he's way more of a conventional 15W40 guy, he said he'd personally run a 5W40 synthetic, due to it's ability to handle a hotter operating temperature over a longer interval, and that the areas you're running your truck in have hotter ambient temperatures for more months of the year compared to what we see in Utah.

And honestly, after reading all of the information found in the responses posted in this thread, I think if it was my pickup, I'd also run a 5W40 year round for the added piece of mind.

 

[userfriendly]

After reading all the posts, I would be tempted to run Duron E 20w50 spring, summer and fall, and 0w40 or 5w40 in the winter.
We always pick out opinions that support our beliefs.
In other words, we believe what we want to believe.

 

[CT8]

Originally Posted By: Garak
Originally Posted By: CT8
I am sure that Doug didn't just look at the wall and say 90,000 is a good number and that was that.

Of course not. I don't think anyone suggested that he did.
I am inferring that Doug went through detailed analysis and much testing to find the [comfortable] limits his for fleet maintenance practices. The top fleet managers can get blood from turnips.

 

[userfriendly]

Back in the day, took years and 100s of K miles to determine an oci, and whether synthetic engine oil was more economical than conventional.
Now we can watch YouTube videos from major oil companies tearing down engines with 1m miles,
that ran on Plain-Jane CJ-4 15W40, double the recommended OEM's oci, and the cross hatch still perfect.

If we take fuel economy out of the picture, conventional CI-4+ and CJ-4, depending on fuel sulfur levels,
is good enough for OEM drain intervals.

 

[Garak]

Originally Posted By: userfriendly
After reading all the posts, I would be tempted to run Duron E 20w50 spring, summer and fall, and 0w40 or 5w40 in the winter.

Their 20w-50 isn't even CJ-4 approved.

 

[userfriendly]

Petro-Canada has two Duron 20w50s, classic, and Duron E, April, 2016.
Like their Synthetic 0W40, 20w50 E is "suitable for use" where CJ-4/SN is recommended.
Classic Durons are CH-4/SJ.

 

[CarbonSteel]

Originally Posted By: Dak27
Originally Posted By: 2015_PSD
Originally Posted By: Dak27
I know we have run completely different vehicles in different applications, but I just ended my day in Yuma, Arizona. My truck's dash said the outside temperature reached a high of 115f driving in. I'm hauling a lighter load; 25K lbs on the bills of lading, so add in the weight of my truck and the trailer.

I'm running 15W40 conventional Delvac Super in a Detroit Series 60, and my oil temperature gauge never read above 200f.

Once again, we have completely different vehicles, motors, sump capacities, and applications, but I have zero concerns about a CJ4 conventional 15W40's performance in very hot ambient temperatures. I do however question it's ability to protect my motor during a cold startup in the dead of Winter in the Rockies, Upper Midwest, Northeast, so I switch over to semi-synthetic 10W30 before the coldest Winter months kick in. But many, many big Fleets run conventional 15W40 year round, and million mile motors are very common.

I have a really good friend who runs a repair shop in Utah that works on Ford, Dodge, and GM Diesel trucks/engines. His personal vehicle is a 7.3 Ford Turbo Diesel, he's really knowledgeable on these trucks and motors, if you'd like, I'll ask him about your initial post.
Please do; more information is always a good thing, he just has to remember the 6.7L platform has full emissions controls in place. I am certain the differences in the capacities and systems between an OTR vehicle and mine account for the differences in oil temperature.


I finally was able to chat with my friend about the operating temperatures you've seen with your 6.7. He said in those hot of ambient temperatures, it's not uncommon to see the operating temperatures your engine is showing.

I read him the responses you received from Kendall, Shell, and Mobil in regards to conventional vs synthetic oil operating in hot temperatures.

Although my friend is really Old School in regards to the "Thicker oil is Better" philosophy, and he's way more of a conventional 15W40 guy, he said he'd personally run a 5W40 synthetic, due to it's ability to handle a hotter operating temperature over a longer interval, and that the areas you're running your truck in have hotter ambient temperatures for more months of the year compared to what we see in Utah.

And honestly, after reading all of the information found in the responses posted in this thread, I think if it was my pickup, I'd also run a 5W40 year round for the added piece of mind.

Many thanks for following up!

 

[another Todd]

Originally Posted By: 2015_PSD
I recently went through the mountain passes in southern California with the ambient air temperatures between 110F and 115F and through part of the Mojave desert with an ambient air temperature of 111F. Truck was loaded with four adults and a bed full of luggage and gear and I saw oil temperatures between 220F and 240F for extended times (I maintained speeds of 70+ the whole way). The oil temps would recover fairly quickly on the backsides of the mountains (down to 203F within 5 miles and the transmission temperature never went above 203F).

It did make me wonder what the temps would have been had I been towing. What would be considered the temperature limit for conventional CJ-4 oil? Can it handle 240F under sustained conditions? Any consideration for the turbo? I am (and have been) running either a synthetic 5W-40 or a SynBlend 15W-40. Thanks for your thoughts!


I just returned from a 6400 mile trip pulling a 10K lb. 5th wheel. I left So. Cal and went North through Vegas and then through the Rockies to Denver and beyond. The desert temps were in the 110F range and my oil temps on my 2015 Ford PSD never exceeded 245. Having Shell Rotella 5W-40 in the sump I never gave it a second thought.

 

[another Todd]

Originally Posted By: mbacfp
Thanks for sharing your experience. I've heard that same thing about Rotella T6 from others. Does that mean anything? Probably not...but I agree with your ordering of oils. Maybe someone can chime in...what about an oil that could possibly make an engine sound different in comparison to others? Fairly or unfairly, I've personally stayed away from using T6...went with Valvoline Premium Blue 5w-40 and now Delvac 5w-40 (could not tell any difference between those two oils).


Be careful, especially under warranty...Many 5w-40 synthetic oils DO NOT meet the Ford PSD specification. RT6 Does, Delo 5w-40 DOES NOT.