Yeah catching my problem while the car was still running somewhat normally allowed me to prepare and get the money in order.

Why UOAs?
 

There is significant debate as to whether or not UOAs show any indication at all as to engine wear measurement. I’ve even read from Mobil 1 that they do not and then later on read that they do. Terry Dyson is a hardcore believer in their value to identify the best possible oil for an application for what that’s worth. They are a good measure I think of how the oil itself is doing, but I don’t think the majority of us are really getting our value from them with the exception of 9K who was able to identify coolant ingress. We could better coordinate our oil choice, sampling frequency and such to come up with more valuable trending. For example, a group runs 50wt this summer and another group runs the M1 0w40. All the while tracking avg ambient temps, city/hwy/track, premix, and mpg just to name a few parameters.

I will go back through the thread and make sure I have the 0w40 samples correcting input into my data and repost if necessary and also post my most recent analysis look. This most recent one shows M1 0w40 as being the overall winner, but 10w40 isn’t far behind and could be considered better to those that know more about the rotary than I.

Major parts like what?
If a coolant seal goes, most rebuilds are very standard, not many high wearing parts are reused in any-rebuild, unless you are a tight ass.:)

I mean parts like housings and irons. I would think that having coolant in the combustion chamber would cause excessive wear on those major parts.

that is why it is good to run good synthetic oil which gives you larger margin of extra protection. If I didn't have redline oil in my car my UOA wear numbers would have been much worse especially when you take into account number of track days in those last two samples!

UOAs Averaged Over
 

This is an average of the previous numbers revised to capture all the UOAs and averaging wear metals over OCI mileage.

I would add lead numbers and show the wear per 1000 miles for easier reading.

Nadrealista, I can send you the Excel data if you want to play with it. Just PM me and let me know.

With regard to yet another oil discussion on Canadian Forum, https://www.rx8club.com/canada-forum-35/game-over-natalia-dead-long-live-natalia-long-thread-rant-useful-information-229407/, I said I would post thoughts relevant here to keep things more organized.

To restate if necessary, I’m educated as an accountant and work in the financial reporting and analysis sector of the economy so I’m by no means officially educated in combustion engines or engine oil tribology. But, for the last 13 years I’ve done fairly extensive research into engine oil tribology and internal combustion engine engineering. The analysis I’ve done of our UOAs here has been done out of boredom at work and curiosity, but I’m getting to the point that I’m less convinced that UOAs are an end all indicator of how well an oil is doing at protecting an engine and also that there I'm convinced that there is NO silver bullet of motor oils for our application or any other.

My last PDF analysis of the UOAs was meant to show me of the viscosities we have sampled which showed the least amount of wear metal occurrence overall. As I hope everyone else can see it appears that 0w40 seems to be the best bet overall, but as can be seen its not night and day better and there are tradeoffs. That being said I went a little deeper because the data on 5w30s didn’t seem to make sense. So, because I think there is a factor associated with higher mileage engines I eliminated those with >50K miles which happened to be all 5w30s and 2 belonged to Ferret. Back to Ferret's UOAs in a minute.

For the 5w30s with the high mileage UOAs removed we get an average OCI of 3,548 miles, Avg Alum/mileage of .0009, Chrm/mlg of .0015, Iron/mlg .0066, and Cpr/mlg of .0008. If I compare these results to the other oils 5w30 looks quite good if I consider that lower Chrm is less liner wear, lower Cpr is less bearing wear, less Iron is less rotor and less side iron (also maybe apex seal as I’m not sure what those are made of) wear, and the Alum is on par.

Now Ferret's high Chromium occurrence makes me think that his rotors MAY be moving out of balance from the housing liner and this could be due to overly warn gears/bearings that have looser tolerances causing the movement. So, perhaps there is a need for a 40w, 50w, or even 60w oil to fill in these looser tolerances.

Stealth is right on with the assertion that lighter oils will leave less carbon and they have less overall mass to provide material to be left behind when burned. The same can likely be said for non hydrocarbon based lubricants such as esters (group Vs) found in oil like Redline, Renewable Lubricants, Motul, and MPT to name a few. Less carbon will = less carbon left behind. However, this only applies to niche synthetics like those referenced here. Its pretty common knowledge now that M1, Pennzoil Plat, Synpower, Syntec, and the main synthetics use quite a bit if not entirely Group III or Group III+ petroleum derived base stocks. The exception to this is M1's 0w oils that from what I’ve seen lately are quite possibly an advanced Group IV or PAO base stock and AN Group V to achieve their performance characteristics.

We do have some highly experienced builders on here that swear by 40w and 50w oils. Given their experience in the front lines, so do speak, this should very meaningful. As additional support for this I had a conversation with an oil engineer with Joe Gibbs racing in December where I was told that in testing they did for the military on drones using rotary engines they learned that 20w oil was insufficient at protecting the apex seals and at least a 30wt (they said 10w30) oil was needed. But, if you really want to bake your noodle look at Flashings’ run of 0w20. A pretty good gear/bearing metal # and not too bad housing liner # either.

So all of these observations and data of mine for the better wealth of the community but I’m by no means intending to make any assertion as I simply can’t say for certain even for myself what the best oil is.

Your research and thoughtful analysis has led you to the same conclusion that professionals who test oil for a living reached a long time ago: Oil is Oil

See my "Oil is Oil" links below for two such professionals' opinions.

Yeah, I read that from Blackstone's site years ago. I think about the same time I also read from BITOG more highly esteemed professionals (so the theory goes) indicatig otherwise. So, it took me another few years to get back to this point. Seeing is beleiving right?

"Believing" is thinking something is true despite contrary evidence or lack of evidence. The problem with oil and why things like dino vs. synthetic are referred to as "religious wars" is because there are too many Believers and not enough people thinking, asking questions, and seeking out cold, hard facts. I think oil is mostly just oil, but I'm one of the guys testing mine to confirm or refute that hypothesis. I don't just believe it.

So maybe it's better to say "Facts trump beliefs!" https://www.mdshooters.com/images/smilies/patriot.gif

Semantics

Revs,

What I'm noticing is many 5w30's and lighter oils don't have moly and boron for antiwear, so the uoa's don't look very good compared to 0w40 which is thicker and does have those antiwear adds.

That was my initial thought too, but I didn’t see it in the data I collected. But, then I may be over analyzing and missing the trend. Too bad we can’t post in Excel here bc the data is in a pivot table so it can be manipulated pretty easy to ID trends and such. I agree with you though that Moly and Boron are quite important to this application. I think even the 0w20 flavor of M1 carries a lot or at least a good amount of both which may be why Flashwings run of it showed some promise. I think like you it seems that in the main market available oils M1 0w40 is the best value unless you want to step to niche oils.

If anyone has a good chunk of money to blow on oil MPT might be worth investigating. Its a newer oil being produced by a Redline distributor (ironically) and is rumored to be up to 85% Group V and no VIIs. So, it should in theory be completely shear stable and burn super clean as well as clean to some extent much better than most anything else available either as an oil or secondary additive. It runs about 15$/qrt before shipping I think at Matrix Synthetic oils .com.

I took Iluvrevs data table added my 3 UOAs to it and made some charts to compare the wear per 1kmiles of use for different viscosity. Important thing to note is that 0w20 and 0w30 only have one and 0w40 and 5w40 only have 2 data samples. So those results should probably be taken with some reserve.

First chart combines all main wear metals(averages per 1k miles) for each viscosity. probably a good overall wear indicator:
Attachment 235993

Second chart shows same data individually:
Attachment 235994

I'm afraid the charts and numbers should be taken with a shaker full of salt as they don't take use into account. There's no way 15W40 is going to have higher wear than 5W20 in the same use case. The difference is that the guys running 15W40 are hard track users (as bad as heroin), while I suspect most 5W20 users are street drivers, maybe touching redline once a day. That is going to skew the results.

I had the same thought about the people who run heavier oil are probably pushing their car harder (I wonder how many have forced induction?). And they probably also change their oil more often as well.

If true (and this is of course just speculation) then it means that how you driver your car is more important than what oil you put in it. At least from a wear metal standpoint. Again, speculation, but it makes a certain amount of sense.

But given that carbon buildup is the more common rotary killer, wear metals are probably inconsequential for most people anyway.

Armchair speculations aside, it would be interesting to see the single lowest wear metal report by oil weight, although we should probably toss out any changes with less than 3,000 miles.

Also wonder if there is a correlation between 4 port vs. 6 port and wear metal rate.

One thing I think helped low metals in my good 0w40 uoa is that I put some magnets on my filter to suspend some of the iron.

I'm more worried about antifreeze, dirt, or fuel anyway.

This is my uoa, and I bet the single lowest metal count of anyone's oil.

Oil in one year, and 4 track days!

Only one quart added in 5151 miles, but Mobil 2t premix in fuel.

How many of the UOA's are from Series II engines, and how do they compare against the Series I UOA's for similar miles and usages?

BC.

I think me and Paimon are the only ones. I think what we do have so far shows little difference between SI and SII, but mine were during wear in so not much can be determined from there.

So here are my results with another 3000 miles on RP 5w30.

https://www.rx8club.com/attachment.p...1&d=1331673750

So i dont know ... that is 3 total reports now with lower than spec Visc numbers showing up ... not to mention random crap in my oil apparantly.

I mean the viscosity is not bad but definitely not where my Mobil1 typically is. Not to mention this is during cold weather. I'd like to see how it stands up after 3,000 miles during a Texas summer. It's definitely suitable oil but not very impressive for a boutique oil. I have never been a fan of Royal Purple.

Just for us you should switch to Mobil1, Red Line, or Amsoil for an OIC and see what gives.

I may switch to 0w-40... Im running M1 5w30 now with avg temps around 40 dipping to 20. Its warming up though.