HOHN

Flash point only tells you about the combustion quality of the oil. I don't think that really tells you anything about the lubricating qualities of the oil at elevated temperatures.

What I would be concerned with is film thickness, not flashpoint. The exact same oil in different viscosities will have different lubricating qualities at elevated oil temps. For example, Mobil1 in a 15W-50 will protect much better at oil temps of 260F than would the exact same oil formulation in a 0w-20 viscosity.

Because film thickness the most important quality for a lubricant at elevated temps, and viscosity is the greatest contributor to film thickness, I would say that drawing conclusions about the hi-temp performance of a lube based on flashpoints is mistaken.


This is precisely why hi temps are where synthetics often perform their best, and demonstrate the biggest performance advantage over petroleum oils. Synthetics will often have thicker films even at identical viscosities.

This is why they often have much better Hi Temp Hi Shear (HTHS) values as well.


Oh, and the flashpoint for Delo 400 15W-40 CJ-4 is 399F. https://www.cbest.chevron.com/msdsSe...bus.BusPDSList
The Flashpoint for a Redline 15w-40 is 486F.
http://redlineoil.com/products_motoroil.asp

To me, 87º is significantly more than "5 or 7" degrees.


More to the point of this thread, the lube spec of interest to oil pressure loss at high oil temps is "viscosity index". An oil with a higher viscosity index thickens less as it cools, and thins less as it's heated. Delo has a VI of 131. Redline is 155. This is without a lot of additives designed to enhance VI, too. If the Redline has as many VIIs in it, the VI could be up near 170 (like Redline 5w-40 is). These additive (which the Redline doesn't need) reduce the shear stability of the oil because they shear down, like STP.


The cost/benefit factor is open to a personal interpretation. But the performance advantage of a premium synthetic at high temps (even more than low temps) is not an matter of subjective interpretation-- it is objective fact.

JH

soulezoo

OK, now I don't know a whole lot about this, Justin so I had to look up my favorite juice, Schaeffer's 9000.

Flash point is 440* and the VI is 158.
The one thing that surprised me was TBN is 7.1. But after 20k oil changes TBN is still in the 2's.

HOHN

Thanks to the EPA for ULSD...

cquestad

Hohn...

Jeeezeee...get technical on me.

I ment apples to apples. 15W-40 to the closest to 15W-40 in syn.

The last time I looked up Delo's flash it was 460...so I am lost at that 399 number.
http://www.chevronlubricants.com/wor...multigrade.asp

Lists it at 230 C which is 446 degrees F...but I still remember seeing it higher...more like 460 when I made that decesion last summer.

I have 160k at really high hp...high egts....hard duty cycle...and my engine's guts look brand spanking new...that was enough for me.

I see the point of blending in some 50 wt something in the summer...and the benifit of a month or two of synthetic in the winter...

The rest is a waste of money IMHO. I am sorry if I struck a sore spot Justin.

cquestad

Whoops...wrong link...here is the 460 fl;ash point link...

https://www.cbest.chevron.com/genera...PDS7668618.PDF


BUT............................................... ..........

I am out of the normal...and the new is the LE...and it stinks...399 OUCH!

Justin....should have read up...LE is bad bad bad.

What do you pay for REDLINE?

wap

Do you know if the 55gal drums are still the good old CJ+4 unlike the the new stuff?

I remember it was but didnt know if they had or would change it. We got a drum of it here that I was runnin but switched to amsoil, I may try the delo again after winter (though its not very cold here we may see single digits a couple time a winter) cause, well it would be free oil.

HOHN

No sore spots man-- i hope I wasn't being obnoxious like I can tend to be. (Everyone here knows I have a pedantic side)

I haven't run the Redline for almost 2 years. I was Running M1 T&SUV (the old CI-4 formula) 5w-40, then I went to Premium Blue Extreme.

I'e been running the PB extreme for awhile now. If it weren't for the fact the muy truck rarely gets up to operating temp, I'd probably run a dino oil. As it is now, I'm getting only 20-30 miles a week, and those come in 3 mile chunks, then the truck is shut off. Given my consistently low oil temps, I should probably run an automotive 30wt gasser oil and change it really often like 2K or so.

Justin

renopker

I haven't figured out what it all means but the fact is, twins, bypass,5-40 and a hot motor= loss of oil pressure and thin oil

TexasCTD

Take that thing out and run it!!! It's made to run, not piddle. Take the wife and kid on a long Sunday drive and blow out some soot.

Mine gets driven 60 miles a day whether I want it to or not..

..

cquestad

60-150 min a day here....lol