Okay, so I just bought some royal purple 10w30, firstly because it was on sale. Secondly because I wanted to go a bit thicker for summer.

So far, engine temps are unaffected, as well as oil pressure.

But I took some of the oil to the lab today and ashed the oil to see how much of it is left over after combustion.

I followed the following procedure;

1) remove Pyrex ash crucible from 105 degree Celsius drying oven to a desiccator to cool down to room temperature. (the crucible needs to be ambient temp because hot air rises, and can throw off the scale because of tiny air currents) (the crucible is in the oven because it keeps it completely moisture free)
2) weigh crucible on analytical balance, record weight
3) Tare crucible
4) add oil to crucible
5) record weight
6) burn off the bulk of the matter using a Bunsen burner in a vented fume hood (just so nobody has to smell it as it is combusting)
7) Place in 600 degree Celsius muffle furnace ( 1112 degrees Fahrenheit)
8) wait
9) take crucible out of furnace and place in 105 degree Celsius oven to cool down
10) take out of 105 degree Celsius oven and place in desiccator to get to room temperature
11) weigh, record weight
12) calculate


Anyways, the scale is accurate to four decimal places, and is calibrated daily, along with weekly trends being performed for accuracy.

The scale is approved by the FDA and USDA for pharmaceutical manufacture.

So
41.3644 (crucible + burned oil) - 41.3570 (crucible)
----------------------------------------------------------------
.6139 (weight of oil)


multiply that by 100 = percent unburned at 1112 degrees Fahrenheit for 3 hours.

= 1.2 percent

Its kind of unnerving that 1.2 percent of the total oil injected is not combustible at 1112 degrees Farenheit for 3 whole hours.



Sweet.

tomorrow I will do some regular dino oil

----------------------------
Valvoline 10w30 dino oil

44.0788 (crucible + burned oil) - 44.0746 (crucible)
----------------------------------------------------------------
.6160 (weight of oil)

multiply by 100 = .7 percent



Mobil 1 10w30 synthetic oil

42.6640 (crucible + burned oil) - 42.6600 (crucible)
----------------------------------------------------------------
.5719 (weight of oil)

multiply by 100 = .7 percent



Castrol 10w30 dino oil

40.1356 (crucible + burned oil) - 40.1318 (crucible)
----------------------------------------------------------------
.6123 (weight of oil)

multiply by 100 = .6 percent



So:

Royal Purple 10w30 = 1.2 percent
Valvoline 10w30 conventional = .7 percent
Castrol 10w30 dino oil = .6 percent
Mobil 1 10w30 synthetic oil = .7 percent

Analysis:

The Royal Purple left an oily looking black/purple residue on the bottom of the crucible even after the 3 hour period. It is likely that this would be trace minerals and metals similar to anti seize products. This may be what causes the polishing effect that Royal Purple claims increases the cleanliness of the engine. Also, around the oily blotch on the bottom of the crucible was what looked like a ring of yellow sulfur. Very noticeable. Sulfur in certain molecules is generally not very good for organic things, such as rubber seals or skin for that matter. There is no way to know the causticity of the residue without further analysis.

The Valvoline burned cleaner from the start, it left hardly any residue after the initial burn in the Bunsen burner, and coming out of the 1112 oven all that was left was a small splotch of gray ashes.

So, my interpretation of the two oils is this:

The Royal Purple is made as a lubricant, with superior additives for engine lubrication and heat resistance. This may be a bad thing in an engine designed to consume oil, as the additives have show burning resistance in very high temperatures.

The Valvoline is also primarily made as a lubricant, but its mostly organic nature allows it to burn "cleaner" as it has fewer additives designed to withstand high temperatures (metal ions and such). This may make it better to use in an engine designed to burn the oil. But the downside of this is it seemed that pure carbon was the result of the ashing, a side product of the breakdown of the organic molecules.

Basically you have two choices: Royal Purple = metal and semi-metals in engine, Valvoline = carbon in engine.

I will buy some two stroke, and some other synthetic oils to test.


-*******************

Impressions on Castrol and Mobil 1

The Castrol burned well, with very little soot on the crucible. Results comparable to valvoline.

the mobil 1 burned well also, but strangely enough, left a purple blotchy residue just like the Royal Purple did. Even so, its organic content was greater than that of Royal Purple.

 

This is going to be interesting...

 

Yes it will. My suggestion is to keep posting in the first thread so it's all together.

 

stick in the bee's nest.

 

Isn't 1112°F kinda cool for a combustion test?

 

While the equipment may be capable of 2732 degrees Fahrenheit we do not stock crucibles that can survive in that kind of heat, basically, I could put it in, but it would melt into a puddle of glass on the floor of the oven. That and it would take several hours to change its temperature, which would interfere with the daily operation of the lab

For organics, 1112 is a good temp. Anything that takes higher than that is going to be a heavy metals mix.

 

Even so, at 1.2 percent of total mass, and being the rather pathetic smudge of purple on the bottom of the crucible, it had lost all value as a lubricant. The only thing it could be in an engine after that would be a mess.

 

Have you tried the test with regular dino oil for comparison? Just curious to see how it would compare.

 

What was the consistency of the ash like?

 

did you read the first post???

beers

 

Y'know, my dad warned me I'd go blind but I never believed him...

 

This isn't really going to prove anything as these are not indicitive of the coniditions inside the engine.

 

It will give a relative differene.

 

Just changed my oil 2 days ago, drain the oil, put 4 quarts in, run the engine and *I wanna go fast* out there for 20 minutes, came back, drain, and another 4 quarts.

RP, 5w30

its getting hot in NYC, I guess changing oil more often is a good thing.

the test shows something, but nothing really real life.

Just like the other test that test the oil film strength, it tells us something, but nothing real life.

 

Might not prove anything specific, but it could give a general comparison, right? That's at least what I would think. Though I do realize that the difference as temperatures get higher would be important and could very well change results.

 

update

See first post.

 

Interesting.
I'd like to see the result after something that actually approaches combustion temperatures.

 

Ever notice that RP isn't purple when it comes out of the engine? It's not because it's dirty. Your engine doesn't turn purple either. That's because a crucible isn't indicitive of what happens inside your engine. Go burn some Idemitsu oil. It's got over 1000 ppm of Molybdenum in it. That's 5-10 times more than any other oil out there. See what's left. This test is worthless when determining what oil is best for your engine. Even a UOA is worthless as it doesn't tell you what anything means and you don't know what the original proportions were. I've seen UAO's where the tester claims certain metals are from bearing wear when bearings don't wear! There is never contact with them. That's what the oil is for. There are only 3 metals in your bearings anyways and the one I saw listed wasn't any of the 3.

Don't base ANY opinions on your burning results. You don't have the equipment necessary to determine anything conclusive. You can't even figure out a relative difference in useful terms. This is no more worthwhile than determining a fuel's energy content by burning it in a pan and seeing how fast it ignites.

I will be curious to see how many people panic now and switch oils though. Those people make me laugh.

 

Um, that is how they determine energy content, by burning fuel in a calorimeter. they burn it and measure the heat change. Thats pretty much how they determine energy content for everything, just look up any explosive on wikipedia and you get explosion values. im not saying lighting a beer can of 87 octane and comparing it to a beer can full of 91 octane is a good test, but that is the general principle of how they really measure energy content.

That, and 1000ppm is .1 Percent of the total liquid, clearly within the scope and accuracy of the scale and the test. So yes, if I burned idemitsu oil, I WOULD get .1 percent of sample showing up. If I weighed .6139 grams of Idemitsu, I WOULD get .61 miligrams of molybdenum. Thats not a little, by any means That IS a pile of stuff

Would it make you feel better if I weighed the stuff up on a scale that goes to five decimal places in an anti-static matrix?

Yes, with most organics you are going to get some ashing, that is a fact. Yes, some organics do have no ashing but rather burn to release only water and carbon dioxide.

Yes, its NOT going to be a "normal" organic if it survives higher than 1112 degrees Fahrenheit Its probably going to be some metal or semi-metal complex to survive at that high of a temp. Can you seriously name any?

Yes, my results are reasonable, Royal Purple is a better lubricant, hands down. But what I'm saying is that you have to use some pretty resilient stuff to get those better lubricating qualities.

Now the question that is not "begged" (because there is no way to beg a question without circular argument) but rather implied; is whether this stuff:

1) vaporizes (but keep in mind that your engine is metal, and at vaporization temperatures your oil is probably the least of your worries) Try searching - the boiling point of molybdenum is 8382 degrees Fahrenheit. Considering Iron's is 5182 degrees Fahrenheit. Your engine would be a blob before it actually "got rid of" the molybdenum.

2) Deposits itself on the walls of the engine by reacting to the very high energy environment

3) merely blows out of the engine in the exhaust stream, causing nothing but some soot on your tailpipe.

And yes, my test is not like what happens in an engine. Because in my test, I use an accurate scale and a captive environment for the sample (if there is .1 percent of anything in the sample its going to stay there when I weigh it back).

As a scientist, nowhere did I claim we should all stop using synthetics or all start using dino oil. But rather I go on to state using facts how there is very resilient stuff in Royal Purple that will probably not burn up in the combustion of a street engine of any sort. That coupled with Mazda's claim to not use synthetics paints a picture. How you choose to interpret it is not for me to decide.

 

can I request which oils to burn next? how about motorcraft 5w-20 and the most popular dino oil on this forum, castrol gtx 5w-20

 

So a good quesiton to ask is how likely will that left over crap clog your ports?

What you have is very interesting information, but engine combustion to this day is not that comprehensively understood. Even with all the computing power we have today, car manufacturers have difficultly modeling combustion itself. (not to say they don't do it, but it's not easy, nor flexible)

1% for some reason sounds low to me considering how little oil is part of the combustion. It's not like you're burning only oil. In fact you're burning very little oil. Really interesting stuff, keep at it. Can you compare to Mobil 1? Isn't that the stuff that's known to not burn too well in the rotary? Lets see how it does in the crucible.

 

Good info, lets see how many of the "Synthetic is the only oil to use" people come out and try to defend themselves.

 

My point is that the test is "relatively irrelevant".

So there is some level of "something" that isn't vaporized at 1000* - you might as well measure how "purple" it is (to 5 decimal places, with a computerized colorimeter, etc)....irrelevant.

Like RG stated, many of the "best" oils have high levels of protective metal adjuncts - that is because they were never meant to be part of the regular combustion process.

S

 

Okay, lets take a step back from the mazda issues and look at other companies like bmw, audi, vw, etc. They're facing billions in damages over sludge issues:

http://www.autosafety.org/article.php?scid=151&did=963
http://www.autosafety.org/uploads/ph...WOilSludge.pdf

Guess what they are REQUIRING them to run now? 100% synthetic.


Next you're going to tell me it's not applicable since those are piston cars - not true. Their issues are based on oil change interval and heat issues. Our car has more heat than most. Sludge is an issue in rotary engines too.


As has been said already, burning up the oil in this test just shows how much material can be burned up at 1000 degrees. It doesn't show lubrication properties, or even come close to the amount of heat in the engine to prove anything. In fact, it just shows that royal purple contains more additives that prevent sludge, corrosion, and wear on your engine.

 

i just want him to burn more stuff lol