Toyota says I can't use 0W-30 in the Corolla ...

[artificialist]

ENEOS said that less friction always means less wear, but that isn't entirely true. Many diesel engine manufacturers forbid the use of friction modified oil, stating that it will increase engine wear.

Anyway, I can't find anything wrong with using 0w30 in that engine.

 

[Gokhan]

Originally Posted By: artificialist
Many diesel engine manufacturers forbid the use of friction modified oil, stating that it will increase engine wear.

Do you have any reference on that? I would really like to see it. Most HDEOs contain a moderate amount (~ 50 - 70 ppm Mo and ~ 30 - 200 ppm B) of friction modifiers.

 

[synthetic_crazy]

Gokhan,

Thanks for providing the in-depth information on the 0W-30 oils; I appreciate all the feedback on this posting.

 

[gpshumway]

Originally Posted By: Gokhan
My post meant to be educational as the original poster seemed to be fascinated merely by the thought of having a 0W-x oil, without knowing how it is formulated.

Your statement "All things being equal, a higher VI is better" is wrong. It's simply because all things are never equal when you formulate motor oil and there is always a compromise.

Read my post above. How are you going to obtain a higher viscosity index? You can for example use a lot of viscosity-index improvers, but this obviously makes the oil less stable. You can use a PAO-based oil but it would have stability, seal-compatibility, and lack-of-solvency problems; so, you need to add Group V into it, which lowers the viscosity index and you're back to Square 1. With a PAO-based oil, instead of adding Group V, you can add Group II or III basestocks with high viscosity indexes to solve PAO basestocks' inherent problems I just mentioned but some people won't like that either.

This is exactly the reason why API doesn't even consider "synthetic" a technical term and the word synthetic is not in any part of the API specifications. And this is also the reason why there are a vast number of SAE viscosity grades and motor-oil types -- you need to find the optimal one for your specific application.

You should first learn that all things are never equal in formulating motor oil and there is always a compromise. Then you will start to understand why synhetic is not always superior to dino or 0W-x is not always superior to 10W-x etc.


I realize it's easy to be misunderstood when writing prose to strangers over the internet, but this is really condescending. I know plenty about the compromises required in the design of any system. One of the principal compromises which comes into play is of course cost, a factor which you don't seem to acknowledge in your post above.

Do you know the exact formulations of M1 5w30 and M1 0w30? You've already basically admitted you don't, so why clutter up the tread with a bunch of speculation masquerading as information? Without knowing the exact formulation of the oils in question you can't say anything about the relative shear stability of each oil based on formulation. The only evidence we have is UOA, which of course doesn't say anything about base stock or VIIs.

Let's follow your logic and play amateur oil formulator for a moment...

Oil A - Group II base stock with a VI of 100 plus enough VII to bring the overall formulation to 150 VI plus a standard add pack. Result: Basic 5w30 "conventional" oil.

Oil B - Group III+ base stock with a VI of 140 plus very little VII to bring the overall formulation to 150 VI plus the same add pack. Result: Highly shear stable "synthetic" 5w30 oil.

These two oils will look identical on the PDS, but obviously Oil B is higher quality and more stable and will most likely be more expensive, and of course there's the compromise - cost. So yea, all things are never absolutely equal, but often we can choose the compromise which best fits our situation.

Oil manufacturers and retailers often choose to have varying profit margins on their products for business reasons, providing the opportunity for knowledgeable consumers to find a product which is a particularly good value for their application. Is that not what BITOG is all about?

"Educating" someone with broad generalizations about oil formulation which don't apply to the specific question asked is not helpful, especially considering you don't know how it's formulated either.

 

[Gokhan]

Originally Posted By: gpshumway
I realize it's easy to be misunderstood when writing prose to strangers over the internet, but this is really condescending.

Didn't mean to be condescending.

I think we've discussed the possible advantages of 5W-30 vs. 0W-30 and vice versa to death.

According to the example given by the Mobil above, 0W-30 is not a much worse formulation than 5W-30 -- only 1% more VIIs. One spec that's not listed in that example is the NOACK volatility. I expect the NOACK for 0W-30 to be significantly higher than the dexos1-approved 5W-30 (dexos1 = GF5 + lower [13% vs. 15%] NOACK). 0W-30 is also a little thinner, maybe an advantage for some or disadvantage for others.

Once again, I see very little benefit in using 0W-30 in climates that are not very cold. Only in very climates, you will see some minor fuel-economy benefits, as 0W- and 5W- have nearly the same viscosity down to rather cold temperatures.

Another disadvantage of using 0W-30 is that there is so little choice, especially in US (much more choice in the much colder Canada). So, you're stuck with Mobil 1 here, regardless of how it performs with respect to so many available 5W-30.

 

[OldCowboy]

Originally Posted By: Gokhan

Shearing has nothing to do with the basestocks. It's only determined by the amount and quality of VIIs.


Can you provide a reference to back up this assertion?

 

[Gokhan]

Originally Posted By: OldCowboy
Originally Posted By: Gokhan

Shearing has nothing to do with the basestocks. It's only determined by the amount and quality of VIIs.


Can you provide a reference to back up this assertion?

Monograde oils are considered to be practically nonshearing. The oils that do shear are multigrade oils and the difference from monograde oils is that the multigrade oils contain a viscosity-index improver (VII).

Viscosity-index improvers are characterized by their shear-stability index (SSI):

SSI = 100*(V - V_s)/(V - V_b)

V: fresh-oil viscosity
V_s: sheared (reduced) viscosity
V_b: base-oil viscosity with no VIIs at all but with all other additives

So, by looking at the SSI spec of a particular VII (sold by additive companies), base-oil viscosity, and fresh-oil viscosity, you can calculate how much an oil will permanently shear to a lower viscosity (between the viscosity of the fresh oil and viscosity of the base oil without VIIs).

As a reference, here is a great easy reading on all this, the section in this book pertinent to this discussion being Section 4.1:

Which oil? by Richard Michell

Enjoy!

 

[OldCowboy]

Thanks! I appreciate it.

 

[Gokhan]

By the way, it turns out that this book -- Which oil? by Richard Michell -- hasn't even come out yet. It will start selling in September 2011.

It seems to be a really great read on oil. The author is a very knowledgeable oil professional.

Luckily, some preview of the book is available at the Google Books link I provided and some is available at Amazon.

 

[OldCowboy]

Yep. I read everything at that link and will be buying the book when it comes out.

Thanks again for the info.

 

[steve20]

great reading-thanks for posting the link