AAA Conventional vs Synthetic Oil Study

[kschachn]

Oh I see, forget it then. I thought you were asking because it seemed like a pretty low value for a straight-weight oil. Which indeed it may be, but it illustrates that a good result on this test only means a good result on this test.

But since that wasn't what you meant then never mind.

 

[OVERKILL]

Originally Posted By: merconvvv
Originally Posted By: SonofJoe
Originally Posted By: userfriendly
"The system forces US oils to be far more volatile than they need to be".
Sonofjoe, is that a result of 0W & 5W winter grades attached to OEM approved engine oil for ambient -40C to 50C?
If so, chasing VI and one grade for all climate conditions is incorrect.



The main reason for this is the crazy way ILSAC has organised it's fuel economy tests. If memory serves, a US 5W30 has to have demonstrably better fuel economy than a 5W30 reference oil. Yes, you read it right. It says something must be better than itself!! No doubt this particular piece of madness was done in the name of 'simulating innovation'. The reality is that most US 5W30s have simply been formulated such that they are halfway to being 0W30s (by dropping the CCS, you drop the KV between 0 and 100°C which translates to a fuel economy credit).

For any base oil group, to drop the CCS, you need to lighten the base oil mix making the oil more volatile. If you lighten the base oil mix, you need to add more VII polymer, If you add more VII, you need to lighten the base oil mix a bit more. As often as not, if you add more VII, you need to add a bit more Ashless Dispersant to maintain piston cleanliness. Ashless kills your CCS so you need to lighten up the base oil mix again and the cycle keeps going round and round until you reach equilibrium, but what you always end up with is a oil that is far more volatile than it needs to be.

It's probably also worth mentioning that once you take that first misguided step to say a 5W30 must be better than a 5W30, the impact cascades to all of the other grades, both heavier and lighter.



Thanks for sharing your insight. Pennzoil sn rated sae 30 has pour point of -30c. How is that acheived for an sae 30 ? The viscosity index is close to 105 i think.



Base stock selection or PPD's would be my guess. Perhaps its blended with some GTL? The VI seems too low for any real slug of PAO, which would probably make it a 10w-30 like AMSOIL's and likely wouldn't be cost effective, making GTL more likely.

 

[OVERKILL]

Originally Posted By: kschachn
Oh I see, forget it then. I thought you were asking because it seemed like a pretty low value for a straight-weight oil. Which indeed it may be, but it illustrates that a good result on this test only means a good result on this test.

But since that wasn't what you meant then never mind.


And of course CCS and MRV are not applicable to straight-weights so we have no idea as to how bad or good it would do in that test.

 

[merconvvv]

Is there any production gtl base oil by shell with viscosity around 10-11 at 100c.

 

[SonofJoe]

Originally Posted By: merconvvv
Is there any production gtl base oil by shell with viscosity around 10-11 at 100c.


I can't be 100% sure but I think the answer is no.

All hydrocracking processes involve a degree of 'cracking' heavy hydrocarbons to lighter hydrocarbons. As you up the severity of the cracking process (in going from Group II to II+ to III), you make higher VI stocks but the price you pay is more of the heavier VGO feedstock is destroyed. Group II will leave you with some heavy 500N stock (with a KV100 of 10-ish), Group III might leave you with some 300N (with a KV100 of 7.5-ish). The process by which you make GTL stocks is somewhat different to straightforward hydrocracking but for the sake of argument, think of it as Group III+ and I suspect the heaviest base oil you end up has a KV100 around 5 to 6 cst.

One of the things that most folks don't appreciate is that the shift to Group II & synthetics and the shift to thinner, fuel economy orientated engine oils go hand in hand. You couldn't really have one without the other without causing big supply imbalances.

 

[merconvvv]

To achieve say 10w30 with no ppd i wonder how these 2 would compare
1) blend heavy group ii/ii+ with lighter gtl and no viscosity modifiers
Verses
2) lighter gtl with viscosity modifier.

 

[SonofJoe]

Originally Posted By: merconvvv
To achieve say 10w30 with no ppd i wonder how these 2 would compare
1) blend heavy group ii/ii+ with lighter gtl and no viscosity modifiers
Verses
2) lighter gtl with viscosity modifier.



I'm not sure I can answer the specific question you pose but I can say that ALL 10W30s, from any supplier, will definitely contain Pour Point Depressant (PPD). As a general rule of thumb, you can pass CCS without PPD but you can't pass MRV without PPD. This is most true for Group I oils (which still contain substantial amount of n-paraffins). It's less true as you move to Group II's and Group III/III+ but IMO it's almost inconceivable that any commercial synthetic multi-grade wouldn't contain some PPD.

I might even say that most commercial heavy mono-grade oils (SAE 20, 30, 40 & 50) from reputable suppliers will contain some PPD, even though strictly speaking, SAE J-300 doesn't require these oils to pass either a CCS or MRV test. The treat rate of PPD might only be 0.05% of the oil but even a tiny amount will have a disproportionately big impact on wax crystal modification. Most oil companies would regard the small add-on cost as a price worth paying to avoid field problems.

 

[merconvvv]

Originally Posted By: merconvvv
To achieve say 10w30 with no ppd i wonder how these 2 would compare
1) blend heavy group ii/ii+ with lighter gtl and no viscosity modifiers
Verses
2) lighter gtl with viscosity modifier.


I should have left 10w30 and ppd out of my question.
I was thinking what if you could meet your target ccs mrv viscosity hths with either 1) or 2) then which would one prefer. I guess i was trying to differntiate between pp 10w30 and sae 30 which are apparently 2 different blends.

 

[NO2]

This is a moot argument. Long life synthetics are cheaper per mile and better performing. There is no reason not to use them unless you have high oil consumption.

For my Honda 5Q M1 EP is $15 after rebates + $4 top off 1Q. Filter is $9. Labor is $20. Total $48
Conventional 5Q is $12 x 2, Filter is $5 x2 , Labor is $20x2 = $74.

 

[CT8]

Originally Posted By: Shannow
Originally Posted By: Artem
The only proof I've ever needed on the synthetic vs Dino oil was the frozen pour test done many many years ago (you can find a bunch on YouTube) where Synthetic CLEARLY pours quicker and better then conventional.


In florida ????
Especially in FLA.

 

[4ever4d]

Originally Posted By: NO2
This is a moot argument. Long life synthetics are cheaper per mile and better performing. There is no reason not to use them unless you have high oil consumption.

For my Honda 5Q M1 EP is $15 after rebates + $4 top off 1Q. Filter is $9. Labor is $20. Total $48
Conventional 5Q is $12 x 2, Filter is $5 x2 , Labor is $20x2 = $74.

No it isn't a moot point. Not everyone thinks that synthetic oils are king, because they aren't. They have there purpose and i respect that, but there is a group who still believe in good ol conventional oils and use them to great advantage.

 

[SonofJoe]

Originally Posted By: merconvvv
Originally Posted By: merconvvv
To achieve say 10w30 with no ppd i wonder how these 2 would compare
1) blend heavy group ii/ii+ with lighter gtl and no viscosity modifiers
Verses
2) lighter gtl with viscosity modifier.


I should have left 10w30 and ppd out of my question.
I was thinking what if you could meet your target ccs mrv viscosity hths with either 1) or 2) then which would one prefer. I guess i was trying to differntiate between pp 10w30 and sae 30 which are apparently 2 different blends.



Okay, I think I understand your question now...

Let's say you make two oils. It's actually easier if we do make these as 10W30's as it helps illustrate the points I want to make.

Say we want to base both oils primarily around GTL5. This stuff has a very high Viscocity Index and an extremely low CCS-25. However this stuff has a KV100 of just 5.0 cst and for a 30 weight oil, we need a KV100 of say 10.5. Now adding the DI pack will up the KV100 to say 6.5 cst but that still leaves us with KV100 deficit of 4.0 cst which we have find from somewhere.

Now normally you would first add a heavier base oil from the same base oil slate until you max out on CCS-25. This does two things. It reduces the amount of VII you might need. It also drives the Noack of the final oil down.

However, there is, as far as I know, no corresponding heavy GTL base stock. So in the first instance, we simply add sufficient VII to get the KV100 of the blend to 10.5 cst. This makes for a very poor oil. It has a high Noack and a high polymer loading. Any advantage in using GTL stock is essentially lost.

So for the second blend, we employ a heavy base oil from a different base oil slate; say Group II 500N (note, there are no heavy Group II+ base oils). This stuff has a very high CCS-25 and a very low Noack. Now because GTL5 has such a low CCS-25, we can add a very high percentage of 500N before we hit our CCS-25 limit of 7000 cP max. If we're lucky, we might be able to keep adding 500N until we hit a KV100 of 10.5 cst before we max out on CCS-25, in which case we won't have to add any supplemental VII to the oil. This oil will technically be a mono-grade (a mono-grade by definition contains no VII) but it will in effect be a kosher multi-grade as it meets the 10W30 spec.

If you compare the two oils, the second oil is infinitely superior simply because it has a far lower Noack and contains no VII. It's also almost certainly cheaper to make.

In terms of MRV (assuming both oils contain say 0.1% PPD), the first oil will have a far better MRV but only because the CCS-25 if the oil is inappropriately low.

If I still haven't answered your question, just tell me how and I'll have another bash at it.

 

[SR5]

Great Info Joe,

If I may but in, if they don't make make thick GTL base oil, then how do they make stuff like the GTL Shell Helix Ultra 5W40 ?

Lots of VII or some Group II or some PAO?

Sorry if I've missed something along the way.

 

[SonofJoe]

Originally Posted By: SR5
Great Info Joe,

If I may but in, if they don't make make thick GTL base oil, then how do they make stuff like the GTL Shell Helix Ultra 5W40 ?

Lots of VII or some Group II or some PAO?

Sorry if I've missed something along the way.



At a guess, I'd say they're using heavy PAO as an alternative to heavy GTL. Unlike Group II/II+/III/III+ base oils, there is no 'cracking' involved in the production of PAOs; only 'growing'. You can keep polymerising Decene until you get some extremely viscous grades of PAO (what Exxon calls mPAO). They could use heavy Group II but given that the oil is labelled as a synthetic, ethically, they might not want to do this.

Do be aware however that a 5W40 light GTL/heavy PAO oil will very likely contain a sizable slug of VII polymer.

 

[zeng]

SoJ,
I've a question.
Shell Helix has a blend in 5W40, where, could it be of a blend of Grp II and GTL/medium or light PAO described by you above ?
If so, a blend 5W40 could possibly out-perform Shell synthetic 5W40 light GTL/heavy PAO in terms of oil film thickness/pressure-viscosity coefficient right ?
What about respective performance in terms of VII, Noack etc ?

 

[SonofJoe]

Originally Posted By: zeng
SoJ,
I've a question.
Shell Helix has a blend in 5W40, where, could it be of a blend of Grp II and GTL/medium or light PAO described by you above ?
If so, a blend 5W40 could possibly out-perform Shell synthetic 5W40 light GTL/heavy PAO in terms of oil film thickness/pressure-viscosity coefficient right ?
What about respective performance in terms of VII, Noack etc ?


In theory there could be a difference but TBH, you're at that point where you need to do some serious blending work to figure out the answers to the questions you're asking. Also, whilst I might 'guess' at how Shell might blend their oils, I don't have any hard inside information of what they do in reality. Sorry...

 

[SR5]

As always, thanks Joe.

 

[merconvvv]

Thanks sonofJoe.
That was very helpful.

Heavy Group ii has a noack of around say 2.5, vi of 100 or so, pour point around minus 10 to 15c and flash point around 275 from chevron which is what i could find.

As you explained that very good and cost effective blend would be heavy group ii with gtl resulting in almost no viscosity modifiers and low noack values.

pp 10w30 has noack of 4.7, vi of 150, pp of say -42c. Kv100 of 10.5.
Pyb sae 30 has vi of around 105 pp of -30c kv100 of 11.5 No noack info avail but it looks similar to group ii 500n.

So i think from your explaination above pp 10w30 is not all gtl. Its got a good dose of group ii with low noack.

And a lot of 10w30 s have noack from 10 to 15. I was surprised that shell formula 10w30 had noack around 12. So lets say it uses the same heavy group ii stock as pennzoil platinum. The difference would be gtl for platinum verses group ii non gtl for shell formula 10w30 based on the noack difference between the two.
I might guess that pyb sae 30 has a noack less than pp 10w30 if they are using same heavy group ii in their blends.

Thanks again.

 

[zeng]

Thank you, SoJ.

 

[SR5]

Originally Posted By: SonofJoe

Do be aware however that a 5W40 light GTL/heavy PAO oil will very likely contain a sizable slug of VII polymer.

Would a light GTL and heavy Group III be possible ?