Oil: Royal Purple
- Thread starter JesseH
- Start date
ok i still confused as hell on this but hell if i read it enought time i might get a headack lol
to for weather that ranges from say -10 max to +10 dagrees C i want.. what
15w30?
to for weather that ranges from say -10 max to +10 dagrees C i want.. what
15w30?
silent_sniper said:
From post #11:
jdub said:
Especially for the temp range you specified. You want the oil to flow as well as possible on engine start...that's where the 0W will come into play. Once the motor gets to operating temp (100 deg C), the oil will behave as a 30W. Should be just what you need.
You want the thinest weight oil on startup to increase the life of your bearings, thus the 0W, you want a good level viscosity at normal operating temps for the engine: 30. If you get a bigger viscosity rating oil it's going to show more psi's on your gauge, but it's harder to get the oil through the bearings at normal operating temps. Psi's are the resistance of the oil trying to flow 
.
.This thread obviously remains interesting to a lot of people. Not enough data!
We all agree you need a low first "W" oil number -- the one that describes low temperature, startup viscosity. And further, if you run your turbo in a northern climate, be really careful about spooling it up until the engine is fully up to temperature and then add about 5 minutes before you put your foot into it. The oil line to the turbo is not jacketed, and its warmup lags. I've heard my turbo screech on first boost, right after engine was indicating warm, and the bearings were shot when it was later pulled. Didn't screech any other time.
Yes, go with 5W- or 0W- if starting in subfreezing conditions! And still wait a while after engine hits 180F.
Now, the interesting number is the second one. "Normal" engine operating conditions, are not the problem IMHO! Your lubrication trouble will occur in seriously hard stop-and-go city driving in 90+F summer days with the A/C on.
Your oil cooler fans will be on, if you listen. You still have oil cooler fans don't you?
The oil will be so much above 100 C in the bearing area that the 30 rating (of 0W-30 e.g.) doesn't really describe what is happening. Oil pressure will fall noticeably, but it won't be anywhere near zero, so you might not take notice.
You may then scuff main bearings etc, at really low rpm, if you lug it on a bad start. Some drivers tend to put their foot into it at low rpm A LOT, and in such thin-oil conditions, my guess is their bottom end will go prematurely. It could have been saved with a higher viscosity oil.
I've been running Castrol Syntec 5W-50 for thirteen years. I'm sure in the winter a 0W-anything would be better, but it's not easy to find locally. Maybe I could do better, too, since I've destroyed one turbo bearing...
My point is that it is the extremes of the load/temperature conditions that matter to your oil selection, not the normal everyday situations.
We all agree you need a low first "W" oil number -- the one that describes low temperature, startup viscosity. And further, if you run your turbo in a northern climate, be really careful about spooling it up until the engine is fully up to temperature and then add about 5 minutes before you put your foot into it. The oil line to the turbo is not jacketed, and its warmup lags. I've heard my turbo screech on first boost, right after engine was indicating warm, and the bearings were shot when it was later pulled. Didn't screech any other time.
Yes, go with 5W- or 0W- if starting in subfreezing conditions! And still wait a while after engine hits 180F.
Now, the interesting number is the second one. "Normal" engine operating conditions, are not the problem IMHO! Your lubrication trouble will occur in seriously hard stop-and-go city driving in 90+F summer days with the A/C on.
Your oil cooler fans will be on, if you listen. You still have oil cooler fans don't you?
The oil will be so much above 100 C in the bearing area that the 30 rating (of 0W-30 e.g.) doesn't really describe what is happening. Oil pressure will fall noticeably, but it won't be anywhere near zero, so you might not take notice.
You may then scuff main bearings etc, at really low rpm, if you lug it on a bad start. Some drivers tend to put their foot into it at low rpm A LOT, and in such thin-oil conditions, my guess is their bottom end will go prematurely. It could have been saved with a higher viscosity oil.
I've been running Castrol Syntec 5W-50 for thirteen years. I'm sure in the winter a 0W-anything would be better, but it's not easy to find locally. Maybe I could do better, too, since I've destroyed one turbo bearing...
My point is that it is the extremes of the load/temperature conditions that matter to your oil selection, not the normal everyday situations.
:3d_frown: Sigh...I really wish the 50W oil myth would die. Steven I've went over this many times here on SM...do some more research and you would find all the data you can digest.
5W-50 is better than 20W-50, but any 50W is not the best oil for a tight tolerance motor like the 7M...it simply does not flow well through the bearing clearances. Plus, Castrol Syntec is not a true synthetic oil...it begins as a hydrocracked mineral oil. That makes it a Group III oil..that is the base stock of all Castrol oils in the US, except the German Castrol. Mobile 1 was a true synthetic, but it too has switched to a Group III base stock (it appears...jury is still out). The other most common oils here in the US that are true synthetics (Group IV or V) are Redline, Royal Purple and Amsoil.
Gasoline engines are engineered to run at oil temps of 100 deg C...the viscosity measured in centistrokes (cSt) is optimal at 10 cSt. 30W oil has a ISO viscosity of 9.30-12.49 cSt. Here's the chart:
http://www.bobistheoilguy.com/visc.html
You want to use an oil that is close as possible to 10 cSt...if you have bearing wear (like on a high mileage motor), a slightly higher viscosity may be called for. Rule of thumb for a high performance motor, use the oil that will give you 10 psi of pressure per 1,000 rpm. Take a look at 50W viscosity at 100 deg C...it's 16.30-21.89 cSt...a significant increase in viscosity. The hydrodynamics involved in a open bearing like those used on the rod ends and main bearings of the 7M depend on oil film thickness. The tighter bearing clearances in the 7M (and other modern engines) depend on oil flow to maintain film thickness...50W is not better for this purpose.
I pretty much spelled out why a 50W oil is not optimal in this thread beginning at post #80; post #83 and #85 have links, including a white paper by Shell oil showing 5w-20 oil giving higher top ring oil film thickness than a 15w-40 they tested.
http://www.supramania.com/forums/showthread.php?t=12216&page=5
What I saying here is based on a lot of research from various sources linked in the thread above...you wanted data, here it is...where is yours showing a 5W-50 is better for bearings? Here's the info...do with it as you will.
But...your motor...use whatever makes you feel good.
5W-50 is better than 20W-50, but any 50W is not the best oil for a tight tolerance motor like the 7M...it simply does not flow well through the bearing clearances. Plus, Castrol Syntec is not a true synthetic oil...it begins as a hydrocracked mineral oil. That makes it a Group III oil..that is the base stock of all Castrol oils in the US, except the German Castrol. Mobile 1 was a true synthetic, but it too has switched to a Group III base stock (it appears...jury is still out). The other most common oils here in the US that are true synthetics (Group IV or V) are Redline, Royal Purple and Amsoil.
Gasoline engines are engineered to run at oil temps of 100 deg C...the viscosity measured in centistrokes (cSt) is optimal at 10 cSt. 30W oil has a ISO viscosity of 9.30-12.49 cSt. Here's the chart:
http://www.bobistheoilguy.com/visc.html
You want to use an oil that is close as possible to 10 cSt...if you have bearing wear (like on a high mileage motor), a slightly higher viscosity may be called for. Rule of thumb for a high performance motor, use the oil that will give you 10 psi of pressure per 1,000 rpm. Take a look at 50W viscosity at 100 deg C...it's 16.30-21.89 cSt...a significant increase in viscosity. The hydrodynamics involved in a open bearing like those used on the rod ends and main bearings of the 7M depend on oil film thickness. The tighter bearing clearances in the 7M (and other modern engines) depend on oil flow to maintain film thickness...50W is not better for this purpose.
I pretty much spelled out why a 50W oil is not optimal in this thread beginning at post #80; post #83 and #85 have links, including a white paper by Shell oil showing 5w-20 oil giving higher top ring oil film thickness than a 15w-40 they tested.
http://www.supramania.com/forums/showthread.php?t=12216&page=5
What I saying here is based on a lot of research from various sources linked in the thread above...you wanted data, here it is...where is yours showing a 5W-50 is better for bearings? Here's the info...do with it as you will.
But...your motor...use whatever makes you feel good.
It's ok, I'm a newbie on this list and thank you for the references. There's a lot to plough through and a lot of good advice, so it helps to have pointers.
If Castrol is just a hydrocracked crude cut plus additives, I'm wondering why I should pay a premium for it. That is very interesting.
I worked one summer (long ago) in the lubricants lab at Imperial Oil, Edmonton, so I know that most oil blending stock is partly or totally hydrocracked. Nothing special about that. It is a way to clean up mineral oil so it is less oxidation-prone, and lowers costs because it increases yield of light oil from heavy oil.
Synthetics are (were? technology advances...) made by linking two fatty acids (like stearates) in a round-about way, into an ester, if I recall. Maybe this has changed? This makes a very polar center to the molecule that results in a greater stickyness to metal....Harder to scuff off the monolayer on the metal. Also, because the rest of the molecule is aliphatic and very hard to oxidize, the synthetics can last longer -- at least if the limiting thing is oxidation.
Further, synthetics should need less viscosity index improvers. VI improvers are (were?) polymers that expanded their solution volume in oil at higher temperatures, and thus countered the tendency of a plain oil to drop in viscosity.
The problem with these polymers is that they get chewed up by mechanical stresses and oxidation, so the high temperature index of the oil will drop as it ages in use. What starts as a 5W-50 oil can be maybe 5W-20 after hard use, or worse. (The lower number will not change much.)
Synthetics are inherently better at holding a more constant viscosity as temperature rises. They should need less VI-improver additives and therefore be less aging/wear-prone. If Castrol has crapped out and substituted mineral oil under the same label....egad!
All it would take to tell the difference, is 20 minutes on an infrared spectrometer. I think maybe I can swing that at a local lab for cheap. They drive cars too! I'll see if I can compare Mobil 1 and Castrol Syntec and some plain-jane mineral oil. More on this in a week or two.
I agree with the argument that a certain volume of oil has to flow into bearings, and this is engineered for a specific oil viscosity - maybe 10 centistokes...that part of the argument is fine.
My doubts have to do with how hot the oil can get in an engine putting out more power than its engineers intended - as you, me and a lot of folks on this list do on a regular basis. Is it not arbitrary to refer to its viscosity at 100C? The pump output to the bearings might be running 150C for short periods... who knows?
I'm in agreement that 5w-50 isn't the optimum on a cold winter day. But I drive Miss Moneypit all winter! Weather being as crazy as it is now, here in Toronto in January it could be anywhere from -30F to +60F. I only do 6000 mile a year recently, so oil changes based on milage can come in any season. My strategy has been to buy the highest viscosity index available and be sure the whole motor bay is truly warmed up before buzzing it.
If other circumstances, then other solutions...no?
If Castrol is just a hydrocracked crude cut plus additives, I'm wondering why I should pay a premium for it. That is very interesting.
I worked one summer (long ago) in the lubricants lab at Imperial Oil, Edmonton, so I know that most oil blending stock is partly or totally hydrocracked. Nothing special about that. It is a way to clean up mineral oil so it is less oxidation-prone, and lowers costs because it increases yield of light oil from heavy oil.
Synthetics are (were? technology advances...) made by linking two fatty acids (like stearates) in a round-about way, into an ester, if I recall. Maybe this has changed? This makes a very polar center to the molecule that results in a greater stickyness to metal....Harder to scuff off the monolayer on the metal. Also, because the rest of the molecule is aliphatic and very hard to oxidize, the synthetics can last longer -- at least if the limiting thing is oxidation.
Further, synthetics should need less viscosity index improvers. VI improvers are (were?) polymers that expanded their solution volume in oil at higher temperatures, and thus countered the tendency of a plain oil to drop in viscosity.
The problem with these polymers is that they get chewed up by mechanical stresses and oxidation, so the high temperature index of the oil will drop as it ages in use. What starts as a 5W-50 oil can be maybe 5W-20 after hard use, or worse. (The lower number will not change much.)
Synthetics are inherently better at holding a more constant viscosity as temperature rises. They should need less VI-improver additives and therefore be less aging/wear-prone. If Castrol has crapped out and substituted mineral oil under the same label....egad!
All it would take to tell the difference, is 20 minutes on an infrared spectrometer. I think maybe I can swing that at a local lab for cheap. They drive cars too! I'll see if I can compare Mobil 1 and Castrol Syntec and some plain-jane mineral oil. More on this in a week or two.
I agree with the argument that a certain volume of oil has to flow into bearings, and this is engineered for a specific oil viscosity - maybe 10 centistokes...that part of the argument is fine.
My doubts have to do with how hot the oil can get in an engine putting out more power than its engineers intended - as you, me and a lot of folks on this list do on a regular basis. Is it not arbitrary to refer to its viscosity at 100C? The pump output to the bearings might be running 150C for short periods... who knows?
I'm in agreement that 5w-50 isn't the optimum on a cold winter day. But I drive Miss Moneypit all winter! Weather being as crazy as it is now, here in Toronto in January it could be anywhere from -30F to +60F. I only do 6000 mile a year recently, so oil changes based on milage can come in any season. My strategy has been to buy the highest viscosity index available and be sure the whole motor bay is truly warmed up before buzzing it.
If other circumstances, then other solutions...no?
Steven - It looks like you have a good handle on lubricants...it is a lot to plow through and just might change your mind about using a 50W oil. Here's something to consider....take a look at this chart:
http://63.240.161.99/motoroil/oildatasheets.html
Lets compare viscosity at 40 deg C and 100 deg C for Castrol 5W-30 and Castrol 5W-50:
Castrol Syntec 5W-30
40 deg C - 53 centistrokes
100 deg C - 9.7 centistrokes
Castrol Syntec 5W-50
40 deg C - 110 centistrokes
100 deg C - 17.5 centistrokes
As you can see, there is a significant difference in viscosity...a 108% increase at 40 deg C and an 80% increase at 100 deg C. Keep in mind the lower number means the oil is going to thicken less when cold...the lower the number, the less it thickens. However, this number applies to oil in grade...a multi-grade 50W oil is still a 50W oil and is thicker as a result. Therefore the 5W rating on a 5W-50 is much thicker than the 5W rating on a 5W-30. A 5W-50 oil will not flow through the bearing clearances as well as a 5W-30 to maintain the oil film thickness required to keep your bearings doing their job.
Now, take a look at the chart again...true synthetics (Group IV & V) like Redline, Amsoil, and Royal Purple are actually a bit thicker than Castrol Syntec (in grade...5W-30 for example) for viscosity at 40 deg C and 100 deg C. About 62-65 centistrokes at 40 deg C and 10.6-11.7 at 100 deg C for all 3 synthetics. Of course this has a lot to do with the way the oil is formulated, but does shoot down one of the most common things you hear about synthetics..."synthetics are thinner than mineral oil"...it's simply not true.
Concerning the localized heat caused by friction inside the bearing. Would it not be better to have the flow to keep the bearings cool? That is one of the functions of oil in any motor and in a high HP 7M, it's even more so. The ability to maintain oil film thickness of a 30W multi-grade is superior to a 50W multi-grade...if the problem is heat (one part of the puzzle), the ability of the 30W to flow will help keep the bearings cool and at the 100 deg C operating temperature. A better alternative (vs. using a 5W-50) would be to upgrade the oil cooler to handle the extra heat from a built 7M engine.
IMO a 0W-30 or 5W-30 full synthetic is a better choice for your engine in the climate you have in Toronto. If you have a lot of miles on your motor, use a 40W multi-grade with the lowest cold rating you can get. You will lose some oil pressure compared to the 5W-50 you're running now, but you will gain flow and that's what you want...keep in mind the 7M oil system is a low pressure, high volume system. As long as you are getting 30-40 psi of pressure at 3,000 rpm (assuming street use) the lower weight oil will be better for your engine.
Yes...Castrol Syntec (except the German Castrol I mentioned) is just a hydrocracked crude plus additives...a Group III oil. Castrol Syntec is not made with PAO (polyalphaolefin) synthetic molecule base stock, yet because of legal finagling with the definition of synthesized motor oils they can legally be called synthetic. It looks like Mobil 1 is heading down the same path...it's a rip-off IMO to pay synthetic prices for a Group III oil. Not that Castrol Syntec is a bad oil...it's the price they charge...I expect to get what I pay for. If you have access to a spectrometer, that's outstanding....I would love to get an independent confirmation to see if Exxon is pulling the same trick as Castrol.
Here's a couple of links for you....the 1st is by Dr Haas. He has a few high end toys and knows more about motor oil than I ever will. The 2nd is to an oil forum I look at from time to time...as with any forum, there's a lot of opinions and conjecture, but has a lot of good info too.
http://63.240.161.99/motoroil/
http://www.bobistheoilguy.com/
tekdeus - No offense, but there would be a blizzard in hell before I would use any oil additive. Modern synthetics have a robust additive pack and there is no need for any additional additive. I don't know about Bi-Tron, but Slick 50 is simply chunks of teflon in suspension...Lucas will emulsify causing all kind of problems. The only thing I would ever do is add a half quart of an POE (ester) base stock oil to a PAO oil as a seal conditioner and even that is really unnecessary. IMO, oil additives are just a lot of marketing hype to get my hard earned $$$.
http://63.240.161.99/motoroil/oildatasheets.html
Lets compare viscosity at 40 deg C and 100 deg C for Castrol 5W-30 and Castrol 5W-50:
Castrol Syntec 5W-30
40 deg C - 53 centistrokes
100 deg C - 9.7 centistrokes
Castrol Syntec 5W-50
40 deg C - 110 centistrokes
100 deg C - 17.5 centistrokes
As you can see, there is a significant difference in viscosity...a 108% increase at 40 deg C and an 80% increase at 100 deg C. Keep in mind the lower number means the oil is going to thicken less when cold...the lower the number, the less it thickens. However, this number applies to oil in grade...a multi-grade 50W oil is still a 50W oil and is thicker as a result. Therefore the 5W rating on a 5W-50 is much thicker than the 5W rating on a 5W-30. A 5W-50 oil will not flow through the bearing clearances as well as a 5W-30 to maintain the oil film thickness required to keep your bearings doing their job.
Now, take a look at the chart again...true synthetics (Group IV & V) like Redline, Amsoil, and Royal Purple are actually a bit thicker than Castrol Syntec (in grade...5W-30 for example) for viscosity at 40 deg C and 100 deg C. About 62-65 centistrokes at 40 deg C and 10.6-11.7 at 100 deg C for all 3 synthetics. Of course this has a lot to do with the way the oil is formulated, but does shoot down one of the most common things you hear about synthetics..."synthetics are thinner than mineral oil"...it's simply not true.
Concerning the localized heat caused by friction inside the bearing. Would it not be better to have the flow to keep the bearings cool? That is one of the functions of oil in any motor and in a high HP 7M, it's even more so. The ability to maintain oil film thickness of a 30W multi-grade is superior to a 50W multi-grade...if the problem is heat (one part of the puzzle), the ability of the 30W to flow will help keep the bearings cool and at the 100 deg C operating temperature. A better alternative (vs. using a 5W-50) would be to upgrade the oil cooler to handle the extra heat from a built 7M engine.
IMO a 0W-30 or 5W-30 full synthetic is a better choice for your engine in the climate you have in Toronto. If you have a lot of miles on your motor, use a 40W multi-grade with the lowest cold rating you can get. You will lose some oil pressure compared to the 5W-50 you're running now, but you will gain flow and that's what you want...keep in mind the 7M oil system is a low pressure, high volume system. As long as you are getting 30-40 psi of pressure at 3,000 rpm (assuming street use) the lower weight oil will be better for your engine.
Yes...Castrol Syntec (except the German Castrol I mentioned) is just a hydrocracked crude plus additives...a Group III oil. Castrol Syntec is not made with PAO (polyalphaolefin) synthetic molecule base stock, yet because of legal finagling with the definition of synthesized motor oils they can legally be called synthetic. It looks like Mobil 1 is heading down the same path...it's a rip-off IMO to pay synthetic prices for a Group III oil. Not that Castrol Syntec is a bad oil...it's the price they charge...I expect to get what I pay for. If you have access to a spectrometer, that's outstanding....I would love to get an independent confirmation to see if Exxon is pulling the same trick as Castrol.
Here's a couple of links for you....the 1st is by Dr Haas. He has a few high end toys and knows more about motor oil than I ever will. The 2nd is to an oil forum I look at from time to time...as with any forum, there's a lot of opinions and conjecture, but has a lot of good info too.
http://63.240.161.99/motoroil/
http://www.bobistheoilguy.com/
tekdeus - No offense, but there would be a blizzard in hell before I would use any oil additive. Modern synthetics have a robust additive pack and there is no need for any additional additive. I don't know about Bi-Tron, but Slick 50 is simply chunks of teflon in suspension...Lucas will emulsify causing all kind of problems. The only thing I would ever do is add a half quart of an POE (ester) base stock oil to a PAO oil as a seal conditioner and even that is really unnecessary. IMO, oil additives are just a lot of marketing hype to get my hard earned $$$.
HellsLegion said:
If you're going to spend the $$$....IMO the additive pack is better in Redline (a 100% ester base stock). Get the 5W-40 if a 40W is what you want to use.
jdub, you are being persuasive.
I looked over the oil FAQ, bobistheoilguy, read Dr Haas, and read the oil spec sheets, before I ever posted anything on this list on anything. It was the first thing that caught my eye when I came to the list.
Still left me with "yes, but..."s, hence my wading in here on the topic.
I've been watching my oil gauge through warmup... and thinking of times I ran out of cooling capacity...but it is too late tonight to get into the issues I still have with some of these arguments. And I want to check which of your reading suggestions I haven't seen yet, and read them.
Let me see on Monday whether my old lab colleagues will run - or maybe already have run - some of these "synthetic oils" on an IR, especially Mobil. I have used Mobil 1 at times and it is easily available locally (same price as Syntec).
The lab does a lot of things, but sometimes runs oil analyses for fleets and warrantee cases - cut open the filters, inspect any residue under a microscope, run ICP metals analysis if found, infrared the oil for oxidation and contaminants. We used to do it on our own cars too. They don't have a viscosity bath set up though.
Regarding oil supplements - do you also not favor Molyslip, on the argument that modern additive packages are very good?
I looked over the oil FAQ, bobistheoilguy, read Dr Haas, and read the oil spec sheets, before I ever posted anything on this list on anything. It was the first thing that caught my eye when I came to the list.
Still left me with "yes, but..."s, hence my wading in here on the topic.
I've been watching my oil gauge through warmup... and thinking of times I ran out of cooling capacity...but it is too late tonight to get into the issues I still have with some of these arguments. And I want to check which of your reading suggestions I haven't seen yet, and read them.
Let me see on Monday whether my old lab colleagues will run - or maybe already have run - some of these "synthetic oils" on an IR, especially Mobil. I have used Mobil 1 at times and it is easily available locally (same price as Syntec).
The lab does a lot of things, but sometimes runs oil analyses for fleets and warrantee cases - cut open the filters, inspect any residue under a microscope, run ICP metals analysis if found, infrared the oil for oxidation and contaminants. We used to do it on our own cars too. They don't have a viscosity bath set up though.
Regarding oil supplements - do you also not favor Molyslip, on the argument that modern additive packages are very good?
i run it and all of my friends run royal purple we all do the same thing filter change at 3k and oil at 5-6k my friend runs it in his meth injected 454 powered drag SA22 rx7 and my other friend runs it in his daily stunted 05 CBR600RR i mean we're talking a bike that sees redline (14k+ rpm) 10+ times a day i run it in my supra also havnt had a problem ever. as long as royal purple is avaible ill never run anything else.
i run a lil on the thick side too 20w50 never had problems with oil pressure or anything.
i run a lil on the thick side too 20w50 never had problems with oil pressure or anything.
jdub said:
My engine burnt a lot of redline i put thru. It may have beenvbacause it was very hot and wi was running a light weight oil.
Thanks for the oppinion
SupaMan said:
Didn't say Royal Purple was a bad oil man...I said IMO the add pack in Redline was better. You might want to rethink running a 50W...the issue is not oil pressure, it's flow through your bearings. But, as I've said before...it's your motor...you can abuse it any way you wish.
HellsLegion said:
Hmmm...burning an ester based oil....that takes some doing. Considering the oil used in the jet engines on the planes I fly are ester based and the temps are a heck of a lot hotter on a turbine drive shaft than a puny Supra motor could ever possibly achieve. I think that burning Redline oil to the point it degrades is :umno:
Now...if you meant you were using oil. That is a different issue...looks like it's getting time for an engine/head re-build. That or you're blowing it out of your turbo seal. the 10W-40 will hold oil usage down for a while, but your days are numbered
Steven said:
A lot of info out there on oil Steven...be careful or you'll turn into an oil geek. Next thing you know, you'll be talking about bypass filtration, oil analysis, and extended drain intervals...LOL
I am very interested in seeing if Exxon pulled a "Castrol" and switched to a Group III base stock. LMK if your friends can make that determination, if you don't mind.
That is correct...I do not believe in additives. The PAO and POE (especially) oils are very good...the ester based oils are king IMO. Like I said above, POE oils are used in jet engines because it resists breakdown due to heat oxidation very well. The temps inside a 7M don't hold a candle to those inside a jet engine. That ability plus the additive packs in the true synthetics make the use of any oil additive you can by completely unnecessary.
I'm not saying the Group III synthetics are bad...they are highly refined and have good additive packs. Having said that, the best oils for a turbo motor is a PAO or POE oil due to the heat from the turbo...they simply resist breakdown much better.