Geek stimuli can never be overrated. I read threads with any kind of data whether I consider it useful or not.

No, it's not. It's about the oil, plain and simple. Issues with oil delivery (or lack there of) will be there whether someone uses the right oil or not. Regardless, the discussion in this thread is about oil that'll maintain its lubricating properties the best in this engine in the posted environments. Compiling a "database", as unscientific as it may be, definitely doesn't hurt to compare exactly how different types and brands of oil are behaving.

eric--glad you came in
several "things" have already been discovered for street driven cars.
1--oil viscosity is NOT holding with the 20-30 wgt oils and with some 40 w oils. They are searing down to one step below (40 to 30,, 30--20 etc) in as little as 1K miles. csct's are below 3.6 for some oils.
2- fuel dilution--can be a problem with short drives and idling warm ups--short drives in my case is 12 miles!! It is very important to get the oil temps up as with cooler ambient temps a lot of people are never seeing oil temps over 160F (open road driving).my last one on a 2K change fuel dilution wa 1.8%--not real high but high enough to affect my viscosity and i am runnig deisel oil!
3- there is abnormal front stationary gear bearing wear in a LOT of engines. Seemingly visocosity related. It is advised to run no lower than a 40W oil--but then again some 40 wgt oils sear fast. So uoa can identify which are holding up and which arent.
olddragger

Yes and I should add that the viscosity numbers were low with the GC 0W-30 I was running and that was only after 1500 miles. After 3,000 miles it would have been much worse.

1. Is it normal for viscosity breakdown in non-rotary engines/are we thinking that this is a problem? Perhaps all oils do this? Just like all milk will ultimately spoil.
2. Don't understand
3. Is this wear the root cause of engine failure? In otherwords is this the one thing that if fixed will make your engine last longer?

I understand the purpose of the thread and I sincerely hope I'm not changing the subject (which I probably am) however something tells (I'm probably wrong) that all this data collection is being done so that people can choose a more optimum oil and therefore make there engines last longer prior to thier demise/need for additional service.

Merry X everyone

I think most engines currently fail now due to low compression - too much heat, too much friction, too much carbon. There are plenty of people blowing up engines in other ways but I guess that could be described as the difference between the motor failing and the user breaking the motor. However, as engines are getting up there in miles people who have had good luck with their premixing, heat, and carbon might start seeing new modes of failure. Engine autopsies seem to indicate that while part A gave first, part B may not have been far behind.

Personally I am on my third Renny despite meticulous oil change intervals and maintenance so I am looking for every little piece of info that may help me to increase the longevity of this engine.

Eric
fuel dilution= blow by and yes some cars are getting enough of this that there is a need to keep an eye on it if you want a 100K engine. I think its mostly driving style and low oil tempt that may be adding to this. Idling until the oil/coolant is "warm" may not be something that you need to do. car runs very rich at cold start idle. Maybe idle just for a few seconds then drive at no higher than 3K rpm with a very little load may be a better way of warming?
bad injectors and poor "crancase" ventilation. can also cause this as you probably know.
2- the rotary seems to sear oil faster than recips--reasons i really dont know--maybe wide babitts and close tolerances?
3- the front stationary gear bearing is going through the copper in as little as 50K. MY THERORY is that if the e shaft has a "wobble" anywhere then that will affect everything.Even rotor stressors/movement. Just my theory, but I KNOW on recips if a main bearing allows wobble then you have big trouble.
enjoy your input as always----Travis did a good picture of you---you aint that good looking!
OD

The RX8Club has become quite the family and or group of friends. It's all about communication and there are many things that people enjoy chatting about. Our cars provide a focal point of common interest.

Oil related issues are not the main cause of engine failures but oil related problems have been identified in a great number of engines. Viscosity breaks down in every type of engine but rotaries do have their own peculiaralities. These types of tests provide information that is useless to some and helpful to others. Just as you pointed out, we can look for signs of deterioration like copper content and other such things.

Paul.

Merry Christmas Paul!
Got the 09 tranny in but it was late before i finished--pilot bearing was shot due too my main shaft play and it put us behind---way behind. So i didnt get to come by. I think i was hallucinating on the way home:) at 2am.

I will forward my 1st uoa to you later. Glad I did it--believe my driving style needs to change and i need to get my oil temps higher than they are. Nothing really abnormal--like wear associated with new engine breakin- but my viscosity even with the.deisel oil was lower than it should have been.
OD
OD

I'm getting oil analysis done to verify my oil is doing it's job of keeping the metal bits from rubbing each other the wrong way. I am tracking the snot out of this car (and hoon it around on the street too), so I want to be aware of unusual wear as early as possible. If the bad metals take a big jump in a report, I'll know that I've overdone it and it's time to get another engine built before catastrophic failure. I'm not getting it done to choose the optimum oil (oil is oil) beyond maybe adjusting the viscosity I use.

And yes, there is some data geek in me that loves spreadsheets...

i sure have learned something---get the oil temps up during everyday driving and dont warm up by idle.
OD

I've been saying that for years; get in and drive :).

Paul.

Stationary gearset loves to shear oils simply from the pressure, hence me recommending the 50w users perhaps try the specialist Millers oil designed for the Mini, as that also shared it's engine oil with the gearbox, under similar conditions, and has a great EP package as a result.
I'll have a word with the rep. when he comes around and see if it's possible for them to tweak a lower viscosity version for us.

i have now blocked both oil coolers (mornings in ga in the 30'sF and warms to the 50's during the day) in efforts to get my oil temps up to 180-200 during my 10-12 mile commute to work.
It helped. It was 36F this morning, warm up was quick-and I got to 180 on the interstate and 185 once in the city. Coolant was 170F or so.
At this point I dont know what else to do--maybe wrap the coolers? Not just block them?
OD

I am going to try and block mine and see what a diff it makes. It's been in the 30's here in the morning too. I noticed some froth on my dipstick when I checked the oil on my road trip and the engine and oil was still hot.

The problem with that logic is the heavier viscosity oils shear much much faster when running at high RPMs and high load.

Edit:

The UOA collection for the Eneos 75w-90 is available here as well.

I'm not recommending a 50w, I'm recommending that those that do use a 50w, try the millers and report back ;)

Personally, I'm sticking with 30w myself.

i think most of us that use 50w is for track only then it is changed out for a 40W?
Doesnt the brand of oil also make a difference in shearing--diesel does not shear as readily as regular engine oil for example?
od

Touche' Phill! I realize I'm being pretty stereotypical with some of my information but I simply don't have the luxary of testing out all these oils. I'm seriously insane about this stuff enough that if I could I certainly would. Posting these UOA's is a great idea and I hope more people post up whatever oils they use whether the experience is postive or negative.

The brand is iffy but certainly the base stock is going to make a difference. Since synthetics use much less VI's you're going to seriously reduce shearing. VI's are the largest molecules so they are the first to go.

Without getting to much into the science since it's off topic I'm starting to actually think that people should be using a thinner (GASP!) oil on the track then they should be on the street. The only major deal breaker would be the oil temperature. Assuming your oil temps are not out of control on the track, the theory holds true. Even still, a thinner oil will flow easier and shed heat better.

Look up information on the hydrodynamic wedge. The short of it is higher RPM's and or bearing speed actually increases your film thickness instead of thinning it like typical judgement would dictate. The Stribeck curve confirms this. As RPM's increase you move from a boundry layer or mixed lubrication into the hydrodynamic region. Since track conditions involve mostly high RPM's it would explain why race motors don't have the same bearing problems that street cars do.

Running a thicker oil on the track won't do any harm but it will greatly increase fluid drag which, in races like the koni challenge, mean losing a few precious horsepower that people with RX8's need.

I'm assuming you do not have an oil thermostat in your system? We have found these to be critical to get to a good operating range. Too big of an oil cooler size/solution (we refer to ours as Pizza boxes) are so effective you get too much cooling---130F max on a late fall/winter/early spring track day. An oil thermo is not as restrictive as we thought (doesn't make the engine run too hot. Our big oil cooler w/oil thermo runs about 185 F all the time. Hot or cold. Something to think about. The "tape" thing can be a "put more on, take some off, put more, take some off" effort.

only have the oem one--which i seriously question. I am beginning to think that an aftermarket may be an option to my mentopausal engine.
Right now with both coolers blocked (front side only) I do get well into the 180's most of the time.
I am getting less milky stuff now and have decided to do 2K mile oil change with a filter change every other time. Still using deisel. I will do uoa on every change for the time being.
I can actually get a tad over 4.5 quarts out by parking on a hill and using an evacuator.
Or use ramps and evac.
OD

OD have you seen the RB oil line kit? I wonder if it will help with pressure and flow while retaining the factory thermos (if you can call them that).

http://www.racingbeat.com/FRmazda4.htm

Funny they say replacing these should be done when the engine is out, it's really not that big of a deal to do with pre made lines. The hardest part for me was cutting, fitting, and adjusting the lines since everything was custom.

Oh, and the price for that kits is ridiculous. You could make those using the best hose and fittings for $200.00 or less.

saw them and at present not interested for that price!
Flash--understand what you are saying and i am certainly seeing the value of used oil analysis.
One of the reasons i like the diesel oil is the higher resistance to shearing. i have been told by someone that works in that business that diesel oils are really as good as some so called synthetics.
I dont know all the tech--i read== but what info do you believe--right?
Running the lightest viscosity oil that meets your engine needs is the best way to go--no doubt. That also goes for the trans and diff:)
Trick is -----finding that right viscosity/oil.
I will be changing oil q 2 K now until i can get a better look as to what is going on.
OD

Yeah they are crazy expensive but there may be better solutions soon.