BOB the oil guy? ever seen this one b4?

[smbrm]

Originally Posted by Suberman

I dunno about that. The oil university stuff is very handy to know.

This one's a bit more down to earth to get started with:

http://www.carbibles.com/engineoil_bible.html

The tire bible pages are top notch also.

While many of these sites provide useful information, they can often include some inaccuracies, but more often, over simplifications, hasty generalizations and poor interpretation of facts and observations leading to skewed conclusions. The casual reader often has no ability to comprehend what information is appropriately explained.

The car manufacturers and oil companies spend millions of dollars developing the skills and credentials of people to be be knowledgeable to deal with these issues and develop products that work together, yet they are often the least consulted, believed or even sought out for understanding?

[Suberman]

Originally Posted by smbrm

While many of these sites provide useful information, they can often include some inaccuracies, but more often, over simplifications, hasty generalizations and poor interpretation of facts and observations leading to skewed conclusions. The casual reader often has no ability to comprehend what information is appropriately explained.

The car manufacturers and oil companies spend millions of dollars developing the skills and credentials of people to be be knowledgeable to deal with these issues and develop products that work together, yet they are often the least consulted, believed or even sought out for understanding?

Yup, bottom line is a good site will give you information that may help you understand that all you need to know about your engine oil is in your owners manual: 0W 20 synthetic oil changed every 6 months (Canada ) or 8,000 km (5,000 miles).

[bluesubie]

Originally Posted by Suberman

I dunno about that. The oil university stuff is very handy to know.

Some of it is good, and some of it is not so good, IMO. I'm not exagerating when I said it was written by a plastic surgeon. He's a very smart dude, but is not formally trained in lubrication (just an oil geek like many of us). This is from the author's professional web site:

As a specialist in wound care and cosmetic plastic surgery, he is uniquely qualified to handle surgeries from head to toe, ensuring your overall aesthetic look is achieved.

Next week, I'll be asking my dentist for oil advice when I go for my semi-annual exam.

Originally Posted by smbrm

While many of these sites provide useful information, they can often include some inaccuracies, but more often, over simplifications, hasty generalizations and poor interpretation of facts and observations leading to skewed conclusions. The casual reader often has no ability to comprehend what information is appropriately explained.

The car manufacturers and oil companies spend millions of dollars developing the skills and credentials of people to be be knowledgeable to deal with these issues and develop products that work together, yet they are often the least consulted, believed or even sought out for understanding?

Where have you been?? You are required to check this forum more often and post here.

-Dennis

[smbrm]

Originally Posted by bluesubie

Some of it is good, and some of it is not so good, IMO. I'm not exagerating when I said it was written by a plastic surgeon. He's a very smart dude, but is not formally trained in lubrication (just an oil geek like many of us). This is from the author's professional web site:

Next week, I'll be asking my dentist for oil advice when I go for my semi-annual exam.

Where have you been?? You are required to check this forum more often and post here.

-Dennis

Dennis, I thought you were looking after everyone! I think you continue to provide a knowledgeably balanced perspective! I do check the forum regularly.

[Dephective]

Originally Posted by Suberman

Yup, bottom line is a good site will give you information that may help you understand that all you need to know about your engine oil is in your owners manual: 0W 20 synthetic oil changed every 6 months (Canada ) or 8,000 km (5,000 miles).

Originally Posted by Mikem53

If your planning on driving your car on the moon or never going below 9000 rpms then that site might give you some useful information...
Otherwise just buy the proper type and grade oil found in the owners manual and you will have all the information you need..

For the average Joe, sure that would be adequate, but there are many of us that require a little more protection. DI is known to cause terrible fuel shear, so you'd want something that would hold up a little better than average oil if you are spending lots of time WOT in the higher RPM ranges. Those that track their car not only see high oil temps for a sustained amount of time, fuel shear + sustained heat = bad for oil. I have dealt with this very issue on a boosted full-time DI car that was terrible on oil. I'm certainly no expert, and while I agree that the manufacturer would definitely be a go-to source for things of this nature, they only take into account the majority of buyers and not applications outside of that market.

So no, that not an end-all be-all one stop shop for information. In fact, there's plenty of evidence to the contrary, but I digress. Point is, if you are anal, or your application is outside the "normal" operating area for whatever reason, it does pay to understand proper maintenance, and with that comes understanding your wear and tear items like fluids.

[smbrm]

So "fuel shear"? A quick google doesn't yield much on the definition of this phrase?
Just curious about what you may be referring to?

[Suberman]

Originally Posted by smbrm

So "fuel shear"? A quick google doesn't yield much on the definition of this phrase?
Just curious about what you may be referring to?

It's actually irrelevant to oil. The issue is fuel deposition on upper cylinder walls which dissolves the oil film. It doesn't matter what oil you use the gasoline will dissolve it. This issue requires tougher top rings is all.

Tracking a car might require oil with higher viscosity than spec but I doubt it. Viscosity isn't the issue. Film strength is and that is not related to viscosity.

[smbrm]

We'll I have never heard in 35 years that phenomena called fuel shear before?The normal reference is fuel dilution when raw non-vaporized fuel gets past the rings into the oil, but starts with what is called fuel impingement on the cylinder walls. Fuel that cannot vaporize for whatever reason has to go somewhere. This has been around for years, and is much better with fuel injection. However asking an engine to ingest more fuel than it's operating temperature can deal with negatively impact this: like being over zealous with the throttle when the engine is cold!

[Suberman]

Originally Posted by smbrm

We'll I have never heard in 35 years that phenomena called fuel shear before?The normal reference is fuel dilution when raw non-vaporized fuel gets past the rings into the oil, but starts with what is called fuel impingement on the cylinder walls. Fuel that cannot vaporize for whatever reason has to go somewhere. This has been around for years, and is much better with fuel injection. However asking an engine to ingest more fuel than it's operating temperature can deal with negatively impact this: like being over zealous with the throttle when the engine is cold!

I found this:

https://www.avl.com/c/document_libra...&groupId=10138

Apparently the issue is DI injectors breaking up fuel which then coats the combustion chamber (and intake valves ) with a thin layer of fuel which displaces lubricant. It seems to me it is a ring design and valve stem problem, not an oil problem.

[bluesubie]

Suberman - I think smbrm is just testing you. He does that to me sometimes if I mis-speak.

I believe the above statement is correct in that the fuel displaces the lubricant. Fuel dilution thins the oil, but doesn't necessarily cause "shearing" (as I understand it).

http://www.amsoil.com/techservicesbu...20Dilution.pdf

It's probably worth mentioning that Blackstone, the most popular uoa lab on bitog and here, doesn't actually test for fuel. They extrapolate the fuel % from the flashpoint reading. It's probably fine if your BS fuel % is low, but if it starts to creep up just keep in mind that a BS type fuel reading will usually be lower than the actual fuel %.

More reading here:

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=968027

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=4637

And note the comment about engine mods and performance chips in the Amsoil document. This is something that folks should keep in mind, if they mod their car and/or race it as Suberman has eluded to. And no, running 5W-40 isn't the answer either.

-Dennis

[smbrm]

Originally Posted by Suberman

I found this:

https://www.avl.com/c/document_libra...&groupId=10138

Apparently the issue is DI injectors breaking up fuel which then coats the combustion chamber (and intake valves ) with a thin layer of fuel which displaces lubricant. It seems to me it is a ring design and valve stem problem, not an oil problem.

The article you quoted provides a good discussion of the subject and of course, their model for evaluation.

As Dennis has eluded, from time to some additional clarity can help keep a discussion on course!

As technology evolves the ability to measure, divide things into smaller and more precise slices and understanding what goes on ever keeps improving.


I find the fascination with UOA wear metals that vary by very low ppm values ( lets say <10-20 ppm, only as an example) to be a bit of a wonder? Folks would benefit from appreciating that every test procedure has an inherent measurement error that is determined by evaluating multiple results of a control sample independent of field samples. In addition to that you are trying to understand a system(oil/engine)that is also prone to large variations from sample to sample, for lots of reasons. So unless you see gross wear metals above recognized benchmark limits, you really should focus on trends established from many oil samples compared with a baseline for your particular engine. And you need at least 4-6 samples on one oil, (particularly at the beginning of the life of an engine when things can be changing a lot) to get any kind of a baseline of what is normal for a particular engine. And even that may not be enough!

So if folks want to debate the minutiae of small differences to help their learning about the subject, that's one thing. Unfortunately, using one or two UOA samplings to evaluate the value of one oil as compared to another has very low capability of telling folks what they think they are trying to learn.

But I'm not trying to start a debate, just sharing, in the hope that some background might provoke some thought towards clarity.

Time to go back to watching!

[bluesubie]

When I first started doing uoa's, I made the mistake of trying to compare an oil based on 1 or 2 uoa's. You will see many people make the same mistake and you simply cannot judge an oil based on one or two uoa's.

I always like to link this article on bitog that was not written by a plastic surgeon, but by someone that has carried out hundreds of uoa's and has consulted and worked with various oil companies.
http://www.bobistheoilguy.com/used-oil-analysis/
He emphasizes that most of these random uoa's are more useful for determining the condition of the lubricant, but not a measurement of actual engine wear.

And here's a good article about why high iron uoa numbers isn't necessarily a good indicator of wear.
http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/2065149/1/Why_iron_ppm_numbers_are_NOT_g

-Dennis

[Suberman]

My take on the DI issue is it isn't a fuel contamination issue at all. I would be very surprised if DI would cause oil contamination but port injection wouldn't. As we all know our little engines run both systems together.

The alleged issue is "washing" of oil off the surfaces in the combustion chamber due to the way the DI spray acts inside that combustion chamber. Since fuel will be injected at some time delta BTDC then the very upper parts of the cylinders may get scrubbed clean leading to possible premature ring wear. The same issue may apparently affect intake valves as the fuel blows back due to valve timing. Usually this fuel and air will return into the combustion chamber shortly thereafter and I do mean shortly!

[bluesubie]

Here's a pretty good uoa trend started on a BRZ.

Note that flashpoint and fuel were pretty good up until 36k and the flashpoint started taking a hit. Also some very long intervals though. I just noticed that in the 26,726 sample, the oil actually thickened to a 30 grade (presumably due to oxidation??).

-Dennis