10w30 synthetics?

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Originally Posted By: CATERHAM
Wow lots of oil myths being perpetuated here.

-What's wrong with VIIs? Nothing, and the best are very shear stable.

-While a super low Noack is nice what's the advantage vs a good Noack in the 9-11% range? Lower oil consumption? Not that anyone can measure. Cleaner intake tract? Not if the oil itself leaves high deposit levels.

And even if you discount the cold start advantages because you live in a warm climate you've still got the increased high temperature viscosity loss due to the oil's low VI.

So I'll pass on the 10W-30 grade for any highly stressed engine I value.
Please link to where 10 or 20 VI points is going to substantially effect the oil's high temp performance?

PP 5w-20 158 VI
PP 5w-30 170 VI
PP 10w-30 150 VI
 
What is the real-world difference in cold start between comparable 5w-30 and 10w-30s when the ambient temp is around 30F/0C? I see lots of specs on visc. at much higher and lower numbers but can't find any practical information about what it means around there, which is "winter cold" in a substantial part of the US.
 
Originally Posted By: hatt
Please link to where 10 or 20 VI points is going to substantially effect the oil's high temp performance?

PP 5w-20 158 VI
PP 5w-30 170 VI
PP 10w-30 150 VI


Given that the two 30s are likely to have similar HTHS, which IS the high temperature operating point in places like the big end, I'm lost with his argument.

Here's some comments from an actual oil formulator in another thread.

http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3944830/Re:_High_V.I._oils,_on_purpose#Post3944830
 
Originally Posted By: Oro_O
What is the real-world difference in cold start between comparable 5w-30 and 10w-30s when the ambient temp is around 30F/0C?


Nothing..they will both be extremely pumpable, and prime the galleries at the same rate...getting where they need to be at same time to all intents and purposes.

The 5W is LIKELY, not guaranteed to have a slightly lower viscous drag, leading to infinitesimally better fuel economy in warmup (and a slightly slower warmup for exactly the same reason).
 
Originally Posted By: hatt
Originally Posted By: CATERHAM
Wow lots of oil myths being perpetuated here.

-What's wrong with VIIs? Nothing, and the best are very shear stable.

-While a super low Noack is nice what's the advantage vs a good Noack in the 9-11% range? Lower oil consumption? Not that anyone can measure. Cleaner intake tract? Not if the oil itself leaves high deposit levels.

And even if you discount the cold start advantages because you live in a warm climate you've still got the increased high temperature viscosity loss due to the oil's low VI.

So I'll pass on the 10W-30 grade for any highly stressed engine I value.
Please link to where 10 or 20 VI points is going to substantially effect the oil's high temp performance?

PP 5w-20 158 VI
PP 5w-30 170 VI
PP 10w-30 150 VI

Happy to.
First you can't compare VIs of different grades so you'll have to rule out the 5W-20 unless you're comparing to a 0W-20.

PP 5W-30 uses higher VI base stocks than PP 10W-30; hence greater high temp' protection assuming both have the same HTHSV.
That said PP 10W-30 does have higher than average VI for a 10W-30 so it is better than most. In fact PYB 10W-30 is likely the same GTL made oil as PP 10W-30 so if you insist on a 10W-30 that would be a good choice.

I had the opportunity a couple of years ago to chat with a GM engineer about the Corvette engines and specifically the spec' oil M1 5W-30. He was asked (not by me) if M1 10W-30 wouldn't be a better choice for track use and he said no. I then quickly asked if that was because M1 10W-30 had a lower HTHSV or a lower VI? Surprised by the informed question, he said he didn't realize the 10W-30 had a lower HTHSV but it was the higher VI of the base oils used in M1 5W-30 that gave greater high temp' protection.
 
In the case of 30w, would this mean the oil with the highest VI would give the best high temp. protection, regardless of HTHS as say in a thicker 30w like a Euro spec. 30w?
 
Originally Posted By: umungus1122
In the case of 30w, would this mean the oil with the highest VI would give the best high temp. protection, regardless of HTHS as say in a thicker 30w like a Euro spec. 30w?


No, HTHS IS the high temp protection, hence the HT in HTHS.
 
Originally Posted By: OVERKILL
Originally Posted By: umungus1122
In the case of 30w, would this mean the oil with the highest VI would give the best high temp. protection, regardless of HTHS as say in a thicker 30w like a Euro spec. 30w?


No, HTHS IS the high temp protection, hence the HT in HTHS.


Yes, the way I see it, HTHS is the value you are after for protection.
 
Originally Posted By: Red91
My 20W-50 conventional flowed fine this morning at 35-40 degrees F. Just saying.


are you trying to wash out your crank bearings or do you not know better?
 
Originally Posted By: Oro_O
What is the real-world difference in cold start between comparable 5w-30 and 10w-30s when the ambient temp is around 30F/0C? I see lots of specs on visc. at much higher and lower numbers but can't find any practical information about what it means around there, which is "winter cold" in a substantial part of the US.


Oil will reach your valve train about a second quicker.
 
Originally Posted By: KingCake
Originally Posted By: Red91
My 20W-50 conventional flowed fine this morning at 35-40 degrees F. Just saying.


are you trying to wash out your crank bearings or do you not know better?


? The 20W designation is qualified for at -20C for MRV and -15C for CCS, he was well above both of those temperatures. Perhaps not an ideal choice for the application but it was within the acceptable temperature range for the Winter rating of the lubricant.
 
Originally Posted By: CATERHAM

Happy to.
First you can't compare VIs of different grades so you'll have to rule out the 5W-20 unless you're comparing to a 0W-20.

PP 5W-30 uses higher VI base stocks than PP 10W-30; hence greater high temp' protection assuming both have the same HTHSV.
That said PP 10W-30 does have higher than average VI for a 10W-30 so it is better than most. In fact PYB 10W-30 is likely the same GTL made oil as PP 10W-30 so if you insist on a 10W-30 that would be a good choice.

I had the opportunity a couple of years ago to chat with a GM engineer about the Corvette engines and specifically the spec' oil M1 5W-30. He was asked (not by me) if M1 10W-30 wouldn't be a better choice for track use and he said no. I then quickly asked if that was because M1 10W-30 had a lower HTHSV or a lower VI? Surprised by the informed question, he said he didn't realize the 10W-30 had a lower HTHSV but it was the higher VI of the base oils used in M1 5W-30 that gave greater high temp' protection.

I meant post a link referring to actual tests and actual numbers. If they have the same HTHS they have the same high temp protection. Unless you're saying the oil actually gets much much hotter. But then you're the guy always talking about running ultra thin oils that inherently have lower HTHS. You've yet to show slightly higher VI leads to tangible benefits inside the engine.

Clearly the "GM engineer" was simply regurgitating the talking points. If he were really concerned with high temp operation he would have recommended M1 0w-40 and not worried about slight nuances of thin ILSAC xW-30 formulations.
 
Originally Posted By: umungus1122
In the case of 30w, would this mean the oil with the highest VI would give the best high temp. protection, regardless of HTHS as say in a thicker 30w like a Euro spec. 30w?

No I'm not saying that.
A Euro spec' 5W-30 or 0W-30 typically have a higher HTHSV of 3.5cP vs 3.0-3.2cP for a typical API SN 30 grade oil.

To clarify, while the temperature at which the HTHSV rating of an oil is quoted (150C (302F) is certainly very hot, it's certainly not the hottest an oil can get in parts of an engine especially if the sump oil temp's get anywhere near that high such as in a racing scenario.
So the greater protection a high VI oil provides, assuming both oils have the same HTHSV rating, would be as oil temp's rise above 150C.
 
Originally Posted By: Oro_O
What is the real-world difference in cold start between comparable 5w-30 and 10w-30s when the ambient temp is around 30F/0C? I see lots of specs on visc. at much higher and lower numbers but can't find any practical information about what it means around there, which is "winter cold" in a substantial part of the US.


Shannow posted this a while back:
http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3891475/Re:_For_those_that_constantly_#Post3891475

Oil%20gallery%20fill%20and%20rocker%20time.jpg


You can see that straight SAE 30, at 30F (-1C) has the oil coming out the rockers at 3 seconds and full oil pressure in 6 seconds. A 10w-30 shows the same 6 second full oil pressure at 9F (-17C) but a slightly longer 10 seconds for the rockers. A 5w-20 at a warmer 12F (-11C) shows the same 6 second full oil pressure time but a lower rocker flow time of 5 seconds, similar to the SAE 30 at 30F. This illustrates that generally, using a lubricant with the appropriate W rating for the anticipated ambient temperatures results in approximately the same amount of time required to reach full oil pressure.
 
Originally Posted By: OVERKILL
Originally Posted By: umungus1122
In the case of 30w, would this mean the oil with the highest VI would give the best high temp. protection, regardless of HTHS as say in a thicker 30w like a Euro spec. 30w?


No, HTHS IS the high temp protection, hence the HT in HTHS.

He said the engineer didn't know that the M1 10w-30 had a lower HTHS than the 5w-30 M1. and the 5w-30 higher VI was the reason it would protect better. If he didn't know the 10w-30 had a lower HTHS, what if it had a substantially higher HTHS than the 5w-30? Do you see what I'm saying, if he had no knowledge of the M1 10w-30 HTHS, why did he claim it was the VI alone?
 
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Originally Posted By: SR5


My dream oil (today) is a full synthetic 10W-30 that is ACEA A3/B4, I've haven't found one yet.


M1 HM 10w-30 is A3/B3.. not sure what the difference is with B4 though..?
 
Originally Posted By: umungus1122
Originally Posted By: OVERKILL
Originally Posted By: umungus1122
In the case of 30w, would this mean the oil with the highest VI would give the best high temp. protection, regardless of HTHS as say in a thicker 30w like a Euro spec. 30w?


No, HTHS IS the high temp protection, hence the HT in HTHS.

He said the engineer didn't know that the M1 10w-30 had a lower HTHS than the 5w-30 M1. and the 5w-30 higher VI was the reason it would protect better. If he didn't know the 10w-30 had a lower HTHS, what if it had a substantially higher HTHS than the 5w-30? Do you see what I'm saying, if he had no knowledge of the M1 10w-30 HTHS, why did he claim it was the VI alone?


He likely assumed they both had the same HTHS.
 
Originally Posted By: OVERKILL
Originally Posted By: umungus1122
Originally Posted By: OVERKILL
Originally Posted By: umungus1122
In the case of 30w, would this mean the oil with the highest VI would give the best high temp. protection, regardless of HTHS as say in a thicker 30w like a Euro spec. 30w?


No, HTHS IS the high temp protection, hence the HT in HTHS.

He said the engineer didn't know that the M1 10w-30 had a lower HTHS than the 5w-30 M1. and the 5w-30 higher VI was the reason it would protect better. If he didn't know the 10w-30 had a lower HTHS, what if it had a substantially higher HTHS than the 5w-30? Do you see what I'm saying, if he had no knowledge of the M1 10w-30 HTHS, why did he claim it was the VI alone?


He likely assumed they both had the same HTHS.

Understood.
 
10W-30 doesn't evaporate as fast as 5W-30 and also doesn't shear near as much.

I think Citgo makes a real good 10W-30 synthetic.
 
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