Most are likely just old school rotor heads and just don't have a good grasp on the topic. Just because you rebuild engines doesn't mean you are an expert by any means. I learned this quickly when I started calling builders for quotes.

Here is my first one, which is from my 2011 Grand Touring. The car had 30,300 miles on it when the sample was taken. The oil in question was about 1,000 miles old and had 1 track day on it. I'm not sure exactly what it is since it was changed by the dealer, but I know it is mineral 5W20 and is potentially Castrol GTX.

As I have mentioned in other threads, my oil change strategy is to take it to the dealer every 3,000 miles for the $20 or $25 standard oil change special, which includes mineral 5W20 and the correct part number (hopefully) OEM filter. After each track day, I drain and fill it myself, which to date has been with Castrol GTX 5W20 or 5W30 from Wally World. Since I average about 11 track days per year, the oil is more or less changed about once per month with 3,000 miles on each filter.

Taking it to the dealer establishes a maintenance paper trail should I have any engine problems while under warranty. I am also too lazy to remove the undertray to change the filter. ;)

I also change the transmission oil (Redline MT-90), differential oil (Redline 75W90), air filter (Mazda), and spark plugs (NGK) once per year. I plan to send trans and diff samples to Blackstone in June out of curiosity.

The car is not my daily driver, and I have averaged about 5,000 miles per year since I have owned it.

Without further comment...
http://cdn-2-service.phanfare.com/im...a1f3588f1273_1

Man for only 1000 miles of use that is crazy when compared to the almost 4000 miles on the Mobil1 UOA listed above.

the other was a reman engine that was also previously owned by someone else, so you can't put too much faith in trying to directly compare the two.

I assume you are referring to the wear metals. Remember that this oil had a track day on it, which means running at an average of 7,200RPM for 2 hours and 155 miles. Quite honestly, I'm surprised this sample looks as good as it does. I expected a lot worse for a mineral 20W oil.

This report seems to validate the idea that it does not much matter what you run as long as you change it [regularly] on an appropriate schedule for the type and quality of oil. That is the conclusion I reached after reading dozens of pages of the oil wars, anyway.

Having said that, my new regimen will include either Rotella T6 5W40 (because Wally World frequently sells it for $16 /5qt bottle) or Mobil 1 0W40 when I do my own drain and fill. That will give me the limited benefits of a quality synthetic blend and a nominal viscosity of 30 most of the time.

I'll order another test or two for future oil changes to see how it affects the report.

I am looking more at the viscosity of the oil compared to others after only 1000 miles. Yeah I realize comparing yours to one of mine or the one of above is kind of pointless, with your being an original engine and a Series II and all. But yeah I agree, the type of oil you choose is not as important as how often you change it.

According to Mazda of Japan a sports car REQUIRES a 30 weight oil. Mazda of USA claims that 30 weight oils voids out warranties and are are illegal because 30 weight fails to meet fuel economy and emission requirements. According to the American Petroleum institute a 0w30 oil gets better fuel economy a 5w20 so again Mazda of USA is wrong and Mazda of Japan is right.

Mazda of USA claims that synthetic oil voids out warranties and caused a race engine to fail because the synthetic did not burn causing deposits on the apex seals which interfered with gas sealing. What Mazda of USA won't tell you is that according to the Society of Automotive Engineers polybutylene synthetic oil was developed for the winning race car of the 1991 LeMans and polybutylene synthetic oil reduced deposits on the apex seals compared with petroleum oil.

Mazda of USA claims that racing synthetic oils are not practical because 2 different types of oils have to be used and this could cause confusion. What Mazda of USA won't tell you is that since the Lemans zero weight oils have been developed that according to Mazda of Japan will reduce deposits on the apex seals resulting in improved gas sealing, reduced wear and longer engine life.

if that oil had only 155 miles on it then multiply your wear numbers by factor of 20, to compare with 3000 miles average wear...doesn't look to good then

for track use 5w-30/40 wt syn oil, no need to change it after every track event.

~1,000 hard city miles plus 155 track miles. Those track miles probably equate to another ~1,000 hard city miles. In that context, this report looks about like it should or even a little better, IMHO.

As I have already stated, I will stop living on the ragged edge soon and at least use a 40W synthetic as my top-off oil and drain and fill oil between dealer oil changes. I'm going to keep letting the dealer do regular oil changes for the paper trail and because they only charge $20 to $25 depending on which coupon I get. I can barely do it myself for that with a Mazda filter and cheap oil. Also, I'm lazy. :P

I think it says 1000 miles on that sample, but that still means aluminum and chrome are approx 3x the universal average, while iron is at 1.5x.

I have had a few reports done now, and it can be hit or miss as to whether the comments take into account the mileage difference between the sample and the universal average or not.

Here's my last report. 2010 Series 2.
The first sample was presumably the mazda recommended castrol 5w20, which I drained when I got the car. The next two are Amsoil 5w30. Both samples have track time on them, and I also double changed it each time to make comparisons a bit harder :) Most of the makeup oil is added at the track, and is probably a conservative estimate. I go through about 1qt per day there, but very little on the street. Despite the comment about the high level of chromium, I think this was actually no more than 2x normal given the extended miles and so quite good considering the track time.

https://cimg6.ibsrv.net/gimg/www.rx8...5b81d14ac3.png

much better report, but you ran it to long. chromium is from rotor housings

Just to start a debate... :)


Are we sure chromium is from rotor housings? Not only is there a not-simple return path from the combustion chamber to the oil system, but there is a much more readily available source of chrome that is immediately in the non-injected oil stream: The e-shaft bearings.

Think about what has to be true for rotor housing chrome to reach the oil pan:
- Chrome wear has to happen
- Oil has to pick up the worn particles before they are flung out the exhaust ports
- That oil has to not be burnt
- That oil has to then either drain between the housing and the side iron (unlikely/impossible?) OR it has to be on top of the engine when the engine is shut off and drain down the iron wall past the rotor's various seals and seep into the static oil supply
- Then it would return to the pan on next startup.

Vs... e-shaft bearing wear that is constantly in the oil stream.

I still have never been convinced that anything from within the combustion area of the engine gets to the oil pan. And if it does, there would have to be many many times as much particles being lost out the exhaust ports.

I would guess via blow-by gases that carry the microscopic particles from combustion chamber to the sump, why do you think oil gets dirty and black? how fuel gets into oil...same way

doubt that bearing have chromium in them, is e shaft coated with chromium?

his lead is low so his bearings are fine.

https://cimg1.ibsrv.net/gimg/www.rx8...7ea1c46efa.png

and if the chromium is coming from e shaft then I would go to 40/50wt oil with higher film strength to prevent metal to metal...

I tracked my S1 pretty hard and it even had small coolant leak, but my chromium numbers were always good (single digits) with 5w-30 redline oil which has film strength of 40wt oil.

Sure looks like it to me:
http://www.tweakit.com/rx7/eshaft1.jpg
(Caption is "RX-8 e-shaft on the bottom. Source: Dispelling Myths: Using RX-8 internals in a 13B-REW)


I guess there is blowby...


But oil gets dirty and black just from heating it. Take a look at this:
http://translate.google.com/translat...ed=0CDUQ7gEwAA

Yeah there is definite blowby and quite a bit of it, especially as mileage increases. This is why you see so much fuel in the oil on rotaries compared to some other engines.

I think at least some chrome is from the e-shaft.
I also think that the level of chrome is not too high given the miles on the oil and the hard use. However, it is high compared to the previous sample, which saw similar track time, but was not run as long, so I could be wrong on that.

Given the condition of the oil, I don't think I did run it too long. It is possible I ran the filter too long though.

I dropped my next two samples off at the post office last night. These are going to be interesting to see when they come back ;-)

And here's what it looks like when things go wrong. Yes, I ran the previous oil long, but that is not what caused the problem. However, if I had changed it and sent it for analysis earlier I would have known there was a problem before taking it back out on track.


https://cimg8.ibsrv.net/gimg/www.rx8...bfe5d877e1.png


RX8 oil analysis

that is one of the advantages of UOA, you can catch the problem before it becomes serious...if you change our oil on time :-)

what is the status of the e-shaft, are you getting new reman trough mazda warranty?

Yeah, the reports work for sure, it saved me from ruining a good core engine by catching a rather small coolant seal failure. We also sent in a sample from a buddies failed engine (turbo, cracked apex) without telling them it was a problem engine and the report came back basically telling us the engine was goners.

blu3dragon, just out of curiosity, why are you running your oil so long? What I took away from reading this thread and some of the oil war threads is that it doesn't much matter what you use as long as you change it every 2K or so for mineral or 3-5K or so for synthetic, and that premium brands do not provide much advantage over good quality regular brands. Yet your strategy seems to be to run a premium oil for extended periods like you would in a piston engine. Care to share your thinking?

I decided to get it rebuilt by myself rather than pursue a claim with Mazda due to the track time and the fact that the car was already apart and would have cost me money to put back together and take to a dealer.

I am lazy and would rather pay more to change my oil less often :)

Once I get my engine sorted, and once it is broken in, I am going to go back to shorter durations but without the double changes.

you can still try to get them to cover the parts/give you reman( I would) then you can put it in yourself?

Out of further curiosity, what do you think did cause the problem and why?

The e-shaft cracked at the output end around an oil hole that is inside the rear main bearing.

Best guess how it happened is a mis-shift that resulted in an over-rev (9500 rpm before I realized and dropped the clutch back in) in Nov 2013 started a small crack that then grew slowly until the last run when it grew enough to set up a wobble in the shaft which then impacted the bearing.

It may also have been a production issue with the e-shaft, or damage caused during assembly or removal of the flywheel, although the flywheel has not been off since the car was purchased new at a dealer.