Overheated

[ShadowsPapa]

Synthetic oil flash points are in the 350-400 deg range, so the oil did not vaporize, shear strength loss starting, yeah prob

Not all of them. Some actually lose protection or even have a breakdown point worse than the best traditional oils.
I'm also talking threshold or onset of thermal breakdown - which is far lower than 300 for some oils.
The onset of “Thermal Breakdown” is determined by the temperature at which the oil begins to smoke/vaporize. This indicates that the lighter components in the oil are beginning to boil off, which changes the oil’s chemical composition for the worse. Always keep your oil below the point of thermal breakdown. If your oil does get too hot, then change it ASAP.

Here are some numbers at which point the oil actually started to vaporize - not enough to cross NOACK numbers, which was way out there until recently. NOACK testing heats oil to extremes for an hour and then measures the loss of volume - that says nothing about the ability to protect or break down point. And yes, it can start to vaporize at 300 or less - and you can bet with coolant at 270 the oil was over 300........
These are points at which the oil actually begins to vaporize:
SYNTHETIC GASOLINE ENGINE OILS:
10W30 Amsoil Dominator Racing Oil, synthetic = 300* F
10W30 Amsoil Z-Rod Oil, synthetic = 300* F
5W30 Pennzoil Ultra Platinum, API SN, GM dexos 1 approved, synthetic = 290*F (high temp tested late 2015)
5W30 Joe Gibbs Driven LS30 Performance Motor Oil, synthetic = 290* F

Further testing showed that some synthetic oils have breakdown temps of lower than the best conventional oils. Averages, yes, synthetics are better, but it's a whopping 10 degrees difference if you average the oils. The AVERAGE synthetic is only 10 degrees better than the average conventional oil.
In short, don't rely on it just being synthetic, make sure it's a GOOD synthetic, otherwise my conventional oil could beat the next guy's synthetic.

Testing has shown that oil protection levels in PSI film strength can drop significantly from 230 degrees compared to 275 - sometimes the protection drops well over 10%.
And the parts that are lost first when it gets hot may not cause instant damage, but it causes trouble down the road. Damage can be long-term, something you'd not notice until into the future.

BTW - AMSOIL is among the best for resisting breakdown and even when operated on the edge, the protection loss is among the least of synthetics.

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[mrmo]

Ok, then why the hell dont we just use dino oil in our Jeeps

 

[ShadowsPapa]

Ok, then why the hell dont we just use dino oil in our Jeeps

Obviously not a fan of probability and statistics, or averages, or........

Let's try this again. you are oversimplifying.

The junk about which is better as far as handling heat is internet lore that's been tweaked and passed along over and over like the old game of telephone. Pretty soon when it gets posted in forums it's "synthetic oil is superior in heat handling" - which is a gross generalization!
Forget all the stuff you read in forums about heat handling.
Worse, they also take only the NOACK numbers, which by the time an oil reaches their test threshold, it's beyond trash. They look only at volume lost, not can it still do the work.

The AVERAGE synthetic oil has a higher onset of thermal breakdown than conventional oil.
AVERAGE - average doesn't mean "all" or even "most"
The average mechanic in a shop is a male - that doesn't mean there aren't a good number of women who could kick their mechanical asses to Jupiter and back.
What all that means is that for THERMAL BREAKDOWN, or resistance to same, there are some conventional oils that beat some synthetic oils for handling heat.
If you happen to choose a synthetic oil that doesn't do too well in heat and I choose a conventional oil that's extremely well rated for heat or thermal breakdown - and both of us overheat our engines, my oil will do better.
However, if you choose the best synthetic and I choose the best conventional oil - your's would do better.
There is synthetic oil out there that's crap, there's conventional oil out there that's pretty danged good.

Ironically, one of the best at handling high pressure, having a strong film that resisted high PSI wear was a bio-synthetic.

These days engines run on the edge, the bleeding edge as we used to call it. Anything off a bit and they suffer.
Oils today are made or formulated to handle the extremes- at least the good oils are.
One example people running the 3.6 need to pay attention to is how the oil handles LSPI
And that's one of the API tests. I really wish AMSOIL would pay the few bucks to get checked out because it's a critical thing moving forward.
An oil may be great under extreme pressures - PSI film strength, it might handle high temperatures and not lose protection, or lose the ability to resist the formations of acid and sludge, but if it contributes to LSPI, it's crap, IMO
So it's a good oil when hot - but now the engine pings under load at low RPM because of the oil.

I will only run oils that pass these tests and are certified because of that. People really have no clue what all of the testing and other processes looks for. They think it's all about viscosity or whatever, and that's hardly the case. Part of one type of testing actually involves - gasp - cam followers rubbing on cam lobes (gee, sound familiar?) guess what these engines have - followers rubbing on cam lobes in high lift mode.

Generally speaking - the best synthetics beat the best conventional oils, but there are conventional oils that will beat certain synthetics in some areas, too.
It's the PACKAGE, the additives, not just the base oil. If it was only the base oil, conventional oils would possibly be gone.

 

[BajaTJ]

Does _EVERY_ thread have to deteriorate into an oil thread? What are the stats on that? ?

 

[wanderer]

So what are the best synthetics.. ? And the other not so good synthetics? And what are the really good non synthetics? And in a pinch what happens if you mix them? Aren’t there blends too ? What are those and how do they perform?

 

[Rusty PW]

So what are the best synthetics.. ? And the other not so good synthetics? And what are the really good non synthetics? And in a pinch what happens if you mix them? Aren’t there blends too ? What are those and how do they perform?

I prefer abiogenic oil.

 

[MrZappo]

Does _EVERY_ thread have to deteriorate into an oil thread? What are the stats on that? ?

100% of oil threads suck 100% of the time. Except on Tuesdays.

There are the stats. As published by the forum gods.

 

[Lunentucker]

I've had to refill mine a handful of times already this summer.

Any indication of where and how you're losing coolant from what is supposed to be a closed loop system?
That would be very concerning to me.

 

[Hootbro]

100% of oil threads suck 100% of the time. Except on Tuesdays.

There are the stats. As published by the forum gods.

In true oil thread fashion, I disagree, they suck on Tuesday also. It is Thursday they do not suck.

I took a auto mechanic correspondence course out of a matchbook 30 years ago so do not doubt my credentials on such matters.

 

[Rusty PW]

In true oil thread fashion, I disagree, they suck on Tuesday also. It is Thursday they do not suck.

I took a auto mechanic correspondence course out of a matchbook 30 years ago so do not doubt my credentials on such matters.

.................and you stayed at a Holiday Inn too............another Prof irwin Corey.

 

[mrmo]

LMAO, well I certainly have wasted several thousand $ over the last years thinking the syn was better in viscosity, heat load, and wear....now Im not sure what I should do...

 

[Hootbro]

.................and you stayed at a Holiday Inn too............another Prof irwin Corey.

Pfffttttt!!! Holiday Inn? Everybody in the know stays in a Motel 6 down by the railroad tracks across from the Methadone Clinic.

 

[Gvsukids]

.................and you stayed at a Holiday Inn too............another Prof irwin Corey.

I think it's the Holiday inn Express showers that are the catalyst.

Any indication of where and how you're losing coolant from what is supposed to be a closed loop system?
That would be very concerning to me.

Have not, yet.

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