0w20 & 5w20 almost identical oil properties

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Originally Posted By: ChrisD46
*Historic school of thought was that the lower the NOACK - the lower the evaporation thus the cleaner intake valves would stay in a GDI engine application ...Now I don't know ? A recent post indicated that a higher NOACK could benefit intake valves in a GDI engine application due to non deposits being the evaporation make up to keep intake valves clean (or something to that affect) .


That was more "junk" science, taking the statements of a research paper and mis applying it.

The statement in the paper was that it was the heavier ends form the deposits, which is NOT equivalent to higher NOACK keeps the valves clean.

Remember that's the same poster who was emphatic that the higher the "W" grade, the better the oil was for your engine only a few short months ago.
 
Originally Posted By: StevieC
I'm assuming the reason they want 0w20 and say that 5w20 is suitable but that you need to go back to 0w20 is to ensure synthetic is used instead.

I'd agree, plus they may "want" 0w-20 for a higher VI, generally, to marginally enhance fuel economy. Note that in my climate, even, I haven't hunted like crazy for a 0w-XX option, though I certainly could find some cheap enough.
 
Originally Posted By: StevieC
Out of these two oils, why wouldn't you use the 5w20 over the 0w20 when the properties are almost identical but the Noack is far superior... Should consideration be given to the V.I. difference?

Your thoughts?



The basic answer is very simple but no one has given it so far. I'll answer it:

The difference is in the CCS -- 0W-20 measured at -35C and 5W-20 measured at -30C, which means that 0W-20 uses a thinner base oil. This results in a lower NOACK for 0W-20. It also results in more viscosity-index improver (VII) for 0W-20 so that the KV100 and HTHSV for the finished viscosities will be in the correct range for an xW-20 grade.

Now, the complicated answer:

One thing we cannot tell from the numbers is the base-oil type. For example, Mobil 1 0W-20 uses a lot more PAO than Mobil 1 5W-20 according to the MSDS. In fact, Mobil 1 Extended Performance 0w20 is mostly PAO. So, in the case of Mobil 1, do you care for more PAO or less VII?

Most importantly, is there any good science that more VII in 0W-20 will result in less wear protection for it than for 5W-20? One can argue that more VII is actually better because it results in a higher viscosity index (VI), which means that a 0w-20 will thin less than a 5W-20 if the temperature rises to, say, 170 C (which is well above the 150 C the HTHSV is measured) in extreme operating conditions. I would think more VII would help you in that case by keeping the oil thick.

Yes, there is this scientific paper by Nissan/SAE that claims that a thicker base oil may be better for timing-chain wear. However, does it really make a difference when a good antiwear/extreme pressure/friction modifier (AW/EP/FM) package is used?

Of course, you also get better fuel economy with 0W-20 than with 5W-20, especially in warm-up situations.

Lastly, NOACK. The only thing that it really affects is the oil consumption but if you don't have oil consumption or your oil consumption is unrelated to NOACK, it's a moot issue. We've already debunked the myth that lower NOACK results in less PCV mist and/or less intake-valve deposits.

For Mobil 1 xW-20 varieties, I would pick Mobil 1 Extended Performance (Mobil 1 Extended Performance) 0W-20 because it's a PAO-based oil unlike any other Mobil 1 variety except the Mobil 1 Annual Protection 0W-20 and Mobil 1 0W-16.

For Amsoil Signature Series (SS), I would probably still pick the SS 0W-20, even though chances are good that both the SS 0W-20 and SS 5W-20 are PAO. A little more VII? Perhaps it's actually better. It's funny that in the past Amsoil had the lowest four-ball-wear number for SS 0W-20 among all of their oils, and now, they put the same number for the entire SS series.
 
Maybe I should go TGMO 0w20.
grin2.gif
 
Originally Posted By: Gokhan
Originally Posted By: StevieC
Out of these two oils, why wouldn't you use the 5w20 over the 0w20 when the properties are almost identical but the Noack is far superior... Should consideration be given to the V.I. difference?

Your thoughts?



The basic answer is very simple but no one has given it so far. I'll answer it:

The difference is in the CCS -- 0W-20 measured at -35C and 5W-20 measured at -30C, which means that 0W-20 uses a thinner base oil. This results in a lower NOACK for 0W-20. It also results in more viscosity-index improver (VII) for 0W-20 so that the KV100 and HTHSV for the finished viscosities will be in the correct range for an xW-20 grade.

Now, the complicated answer:

One thing we cannot tell from the numbers is the base-oil type. For example, Mobil 1 0W-20 uses a lot more PAO than Mobil 1 5W-20 according to the MSDS. In fact, Mobil 1 Extended Performance 0w20 is mostly PAO. So, in the case of Mobil 1, do you care for more PAO or less VII?

Most importantly, is there any good science that more VII in 0W-20 will result in less wear protection for it than for 5W-20? One can argue that more VII is actually better because it results in a higher viscosity index (VI), which means that a 0w-20 will thin less than a 5W-20 if the temperature rises to, say, 170 C (which is well above the 150 C the HTHSV is measured) in extreme operating conditions. I would think more VII would help you in that case by keeping the oil thick.

Yes, there is this scientific paper by Nissan/SAE that claims that a thicker base oil may be better for timing-chain wear. However, does it really make a difference when a good antiwear/extreme pressure/friction modifier (AW/EP/FM) package is used?

Of course, you also get better fuel economy with 0W-20 than with 5W-20, especially in warm-up situations.

Lastly, NOACK. The only thing that it really affects is the oil consumption but if you don't have oil consumption or your oil consumption is unrelated to NOACK, it's a moot issue. We've already debunked the myth that lower NOACK results in less PCV mist and/or less intake-valve deposits.

For Mobil 1 xW-20 varieties, I would pick Mobil 1 Extended Performance (Mobil 1 Extended Performance) 0W-20 because it's a PAO-based oil unlike any other Mobil 1 variety except the Mobil 1 Annual Protection 0W-20 and Mobil 1 0W-16.

For Amsoil Signature Series (SS), I would probably still pick the SS 0W-20, even though chances are good that both the SS 0W-20 and SS 5W-20 are PAO. A little more VII? Perhaps it's actually better. It's funny that in the past Amsoil had the lowest four-ball-wear number for SS 0W-20 among all of their oils, and now, they put the same number for the entire SS series.



On the east coast I haven't seen the better fuel economy using 0w20 over 5w20
Weird maybe but true. I actually see better fuel economy using TT gas over non TT gas.
That I can actually document especially on a hybrid. I haven't seen better mpg from oil down to 7 below- yet.
 
I think another reason they may spec the 0w20 is because this vehicle comes equipped with Start/Stop which I have permanently disabled because it's stupid and just a way for them to cheat CAFE standards.
 
If you don't have to deal with starting your car in extreme cold conditions without a garage and/or a block heater, the SS 5W20 would be a great choice here.
I park outside on ski weekends in the White Mountains with no plug handy and it will drop to ~-30F overnight from time to time...I missed -29F by one night last season, I came up Saturday night instead of Friday night that weekend and it only dropped to about -14F when I was there. I do remember a friend refusing to ski with me a few years ago when it was a balmy -25F as the lifts started spinning. I have never failed to start with 5W30, but had some loooooong cranks back when I ran conventional in my previous vehicle. The battery is definitely a more critical factor to consider than the oil in conditions like that!
Despite my luck with 5W30s in the past (mostly Mobil 1 since I bought my FXT and started learning about CCS, LSPI, and other fun oil things), I have a jug of Mobil 1 Advanced Fuel Economy 0w30 in the garage waiting to go in this winter. My personal prediction is for a warm winter (unfortunately) after it was quite arctic early last season, but I finally saw the AFE with the d1G2 logo and decided to give it a shot (rebate didn't hurt, either). I suspect it will perform just like every 5W30 synthetic from the past 4 years as far as I am able to tell in my daily driving...
 
The coldest it gets here in the winter is about -4F (-20C) more or less. Sometimes colder here/there in February.
 
Originally Posted by StevieC
The coldest it gets here in the winter is about -4F (-20C) more or less. Sometimes colder here/there in February.


You might be OK with a 10WXX if you don't go far from home in the winter...
 
Originally Posted by Virtus_Probi
Originally Posted by StevieC
The coldest it gets here in the winter is about -4F (-20C) more or less. Sometimes colder here/there in February.


You might be OK with a 10WXX if you don't go far from home in the winter...





I would work but if it takes say five seconds for a 10w to get up into the head versus the 1 second for a 0w, then the 0w would be better in my opinion.

The times above are just for example and are not actual pump times.
 
Originally Posted by StevieC
The coldest it gets here in the winter is about -4F (-20C) more or less. Sometimes colder here/there in February.


I doubt there'd be much difference in startup wear reduction between 0w-20 and 5W20 synthetic oils at those temps.
 
How many of you have faith in following manufacturers drain intervals of 10k or once per year on 0w20? Especially if your vehicle is Direct injected. Even worse would be turbocharged and direct injection following 10k OCI.
 
Originally Posted by Oildudeny
How many of you have faith in following manufacturers drain intervals of 10k or once per year on 0w20? Especially if your vehicle is Direct injected. Even worse would be turbocharged and direct injection following 10k OCI.

For starters if I owned a Turbo DI engine mfg. spec or not, 0W20 wouldn't be in the sump.
wink.gif
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And a 10K OCI wouldn't be in the cards either.
 
Originally Posted by Oildudeny
How many of you have faith in following manufacturers drain intervals of 10k or once per year on 0w20? Especially if your vehicle is Direct injected. Even worse would be turbocharged and direct injection following 10k OCI.



For me my oci for GDI or TGDI engines are every 5k unlesss you drive mostly highway and detect no fuel dilution, then 7.5k. I would not do 10k oci but this is my opinion.
 
Originally Posted by Oildudeny
How many of you have faith in following manufacturers drain intervals of 10k or once per year on 0w20? Especially if your vehicle is Direct injected. Even worse would be turbocharged and direct injection following 10k OCI.


My 3.5 Ecoboost was at 85k miles, or so, when an oil change shop messed up causing the engine to blow its oil out and grenade itself. Up to that point, I did the OCI's between 7k and 10k miles. The engine had no apparent issues and ran just like new. The new engine will get the same OCI's. I was running Mobil 1 Extended Performance 5w30, exclusively, btw, I also ran Fram Ultras the last 40k on it. Prior to that, I ran Motorcraft filters, until I realized they were tearolators.

Anyway, with a high quality synthetic, I've got no issue going 10k with that engine, which is about where the OLM puts it.

Most miles on that van are stop and go. The engine does, however, get fully up to temp every day. My wife shuttles kids and drives all over the place.
 
Last edited:
Originally Posted by PimTac
Originally Posted by Virtus_Probi
Originally Posted by StevieC
The coldest it gets here in the winter is about -4F (-20C) more or less. Sometimes colder here/there in February.
You might be OK with a 10WXX if you don't go far from home in the winter...


I would work but if it takes say five seconds for a 10w to get up into the head versus the 1 second for a 0w, then the 0w would be better in my opinion.

The times above are just for example and are not actual pump times.


See, although you put your disclaimer on at the end, that's the problem with this sort of logic...

There's an automatic presumption that 0W "gets there faster"...some on the board have even claimed that of course it gets there faster, even at 100F.

The pumps are positive displacement...they move X volume per revolution", and in the early pressurisation phase are displacing only air.

If the oil is well within it's pumpable range, it will fill the galleries at the same rate regardless.

If it's not in the pumpable range, it's the wrong oil, go down a grade.

I used a 25W70 through a winter in my J car years ago to prove a point on BITOG...oil pressure, and time to get to the cam (oil holes are drilled in the lobes on that engine...very messy with the cap off) was no different to the 15W40 it replaced at sub freezing temperatures.
 
Originally Posted by demarpaint
Originally Posted by Oildudeny
How many of you have faith in following manufacturers drain intervals of 10k or once per year on 0w20? Especially if your vehicle is Direct injected. Even worse would be turbocharged and direct injection following 10k OCI.

For starters if I owned a Turbo DI engine mfg. spec or not, 0W20 wouldn't be in the sump.
wink.gif
27.gif
And a 10K OCI wouldn't be in the cards either.

+1 ! ... A DI turbo is probably called to use a 5W30 or 5W40 oil at most likely no more than 7,500 miles max. OCI . By then that oil is beat to death with soot , fuel dilution , etc.
 
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