What’s With the Oil Viscocity.

Somebody needs to actually read that entire paper, and actually research what those standards mean. TEOST 33c is aimed at turbochargers. 0W-20 still has to pass TEOST MHT-4, which is aimed at piston deposits. Also read the bottom of page 3 "Sequence IIIG" testing, which would also pertain to piston ring deposits.

 

I wonder if the 0w-20 oils with moly are the ones that won’t pass the test because they contain solids (molybdenum)?

 

Any standard conventional5w20, 5w30 and 10w30 ILSAC oils have to and do pass the TEOST 33c. Yet a synthetic 0w20 isn’t tested. I understand the bench test and IIG sequence test difference, I also can make a qualitative determination by broad test exclusion.

 

Thank you for the link! I read it a few times to make sure I understand it enough to comment lol I'm by no means am expert. It said Japanese automakers are excluded because they use a 0w20 with a high moly content. I dont believe moly causes buildup, but I could be wrong. I use Schaeffers oil exclusively in everything I own, and they are well known are one of the leading oil brands and I believe they were some of the first to put moly in oil (could be wrong). The 15w40 I run my ole 7.3 has moly and an excellent additive package with zero deposit buildup (different weight I know, but I dont believe moly makes deposits based on tight injector clearances), I'm gonna email them soon to see what they say about 0w20 regarding this issue and ask for their spec sheet on it. Sorry if this message is a little messy or poorly written. Posting from my phone.

 

Yes my OLD ass has a problem with it too. My guess is this is all about resistance within the engine while running to free up as much horsepower as possible. Even thicker oil when hot slows things down while they are turning. Just my.02

 

This is why many brands have a racing/non-street usage version of 0w20.

 

I have always wondered where I can find the extra slutty variety. Extra virgin sounds boring at my age.

 

I believe it has everything to do with base oil volatility(noack) and polymer viscosity index improvers.

From My historical reading for the past 18 years or so on the subject I can recall The first automakers to recommend 0w20 were Honda and Toyota. This was especially important because it originated for Japanese domestic use.
Japanese vehicles ( vehicles bought and driven in Japan) are not normally retained into high milage due to expensive inspections past a certain age and mileage, yet fuel economy is important. So they biased towards very light lubricants with very high viscosity indexes. Since high mileage used vehicles are not numerous in that nation the long term consequences are not expressed in that domestic location. The USA has different ownership practices.
Past a certain point (170 or so)high viscosity index can be a red flag for excessive use of viscosity index Improvers, those can contribute to deposit formation.


I can go on and on but I have spent many recreational reading years reading white papers and expert writings on the topic and it is not something that can be conveyed in any one thread much less a single post.

The fuel savings was then taken advantage of in the USA to meet tightening regulatory requirements in fleet averages, thus exceptions had to be made..



Personally I have the last bit of 0w20 in my sumps on each my 4 runner and Tacoma. I have alternated heavier grades every 5 k or 6 months through there Toyota CAre period, but will never use it again in either of these vehicles once this last 5 k interval is run out, if I am buying I will buy a superior grade.
I may run 5w20-15w40 synthetics in the years ahead with zero worries. It’s hot as hell in Texas so I am not concerned about cold crank viscosity and 2% or so mileage improvement is inconsequential as an individual. We are all better off keeping stock tire size and street tread with proper inflation versus relying on viscosity for mileage.

 

This is all one needs to know about oil & viscosity.

 

0w-20 is perfectly fine and there are no negligible deficiencies with it as long as you change it every 10k and is why we change it at 10k. Heavier weights like 10w40 and others have longer change cycles.

 

Interestingly, most 10W-30 conventional oils have higher NOACK volatility than do most synthetic 0W-20 oils. Some synthetic oils have little or no VI's in them.

Posts # 26 and #27 are the best and most truthful post in this thread...

 

Now that is have covered the deposit formation gap let me share a post that illustrates the ragged edge that lower viscosity places an engine at in terms of piston ring wear.
For reference

https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/4830433/engine-friction-reduction-trends

The attached paper is very good, the concept of HTHS, but this is the most important expression of viscosity as the SAE grades are very generic and hard for people to grasp what they mean.
Individuals may need some personal research to better understand. a0w20 for example has a minimum HTHS of 2.6. A 30 wt 2.9

This graph shows how wear increases with rpm. It also shows a steep increase with HTHS below 2.6..
Remember oils can shear and experience thinning through fuel dilution with use which can push the HTHS below 2.6 for a 0w20..
https://images.app.goo.gl/6tfaAmapXtgBJWKy9

 

Ok, I've been reading alot on Noack, HTHS, etc. There's alot of debate on this and I dont have a definitive answer as I don't know enough on the subject. From my research I believe Shaeffers will be a good product for me at 0w20 after looking at the spec sheet. It has a HTHS of 5.70 at 212°F and 2.71 at 302°F. This thread has been really fun to be a part of and I've learned alot. My advice, if you're worried about what oil to use, just look at the spec sheet of the oil you plan on using and go from there.

 

I can more or less guarantee that’s not how it works.
We have a dummy light instead of a gauge because they’re likely using a simple pressure based switch - typically set to flick the light on at 8-10psi or less.
It doesn’t care what sort of fluid is in it. Hell, you could put air pressure to it and switch it

 

But i took my Off Road off road and broke the heck out of it!

The internal engine cleanliness with long intervals has nothing to do with Viscosity , it’s oil quality. My BMW, from the previous owner, had oil changes every 10-15k. I had to replace the valvecover gaskets at 100k, and she was real clean inside. The trick is, BMW specs a long-life oil that doesn’t break down so rapidly (and is difficult to find, and $$$) you could use a lesser oil, but you’d have to change it more frequently

 

If you think 0W-20 is thin, how do you feel about 0W-12, 0W-8, and even 0W-4?

"Think Thin: GF-6 Is The Latest Spec In The World of Engine Oil" - https://bit.ly/2NmOGOT

Ed

 

Have you considered just sticking with the OEM Toyota Genuine Motor Oil? It's one of the best 0W-20 motor oils available and there's a lot of oil analysis to prove it.

https://bit.ly/31HLr8x

Just a thought.

Ed

 

I'm sure toyota makes good oil but I've always used Shaeffers. They're the oldest oil company in America, and are famous for their million mile engine teardowns showing virtually zero wear, and their oil exceeds toyota specifications. They really make a fantastic product.

 

There are many parts on your Toyota that Toyota doesn't make. Including oil and filters.

They are someone else's rebadged product. And the low bidder for that particular batch.

Yes, they have to meet 'Toyota specs'. But there is nothing magical about that.

 

Sorry, I just have to laugh at people that think differently than Toyota engineers do! Myself I do not have an engineering degree, so I'll let them do their job, and I'll do mine.