Eighth oil sample
 

2004 Mazda RX-8

Oil OEM Redline Redline Redline Redline Redline
5w20 5w20 5w20 5w20 5w20 5w20 5w20 5w20
Oil added 0 0 0 0 0 0 1 0
Miles on Oil 1250 1764 1500 1500 3000 4000 6581 4400
Miles on Unit 1250 3014 4520 6067 9166 13221 19802 24201
Date 12-13-03 12-30-03 02-09-04 03-24-04 06-04-04 08-30-04 02-15-05 06-10-05

Aluminum 9 5 5 10 6 6 7 9
Chromium 4 5 6 5 6 7 11 13
Iron 30 30 33 29 29 35 50 47
Copper 18 22 15 10 7 6 7 6
Lead 1 2 0 3 3 5 5 6
Tin 0 1 4 0 1 1 1 1
Moly 480 471 578 599 586 556 574 750
Nickel 1 1 1 1 1 1 2 2
Manganese 0 1 1 1 0 0 0 1
Silver 0 0 0 0 0 0 0 0
Titanium 0 0 0 0 0 0 0 0
Potassium 0 2 5 4 3 2 5 1
Boron 137 71 37 24 17 8 14 22
Silicon 42 28 21 17 15 15 15 17
Sodium 8 15 18 20 20 22 20 27
Calcium 1724 2421 2565 2841 2906 3394 2698 3160
Magnesium 5 6 7 6 6 6 14 13
Phosphorous 850 1015 1084 1077 1091 1222 1183 1419
Zinc 884 1236 1165 1236 1362 1371 1304 1533
Barium 1 1 0 0 0 0 0 0

SUS Vis@210C 50.3 50.9 53.4 54.1 54.4 58.5 59.6 62.3
Flashpoint F 335 325 340 370 395 400 370 440
Fuel 1.5% 1.5% 1.3% .5 .5 .5 .5 .5
Antifreeze 0 0 0 0 0 0 0 0
Water 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Insolubles 0.2 0.3 0.4 0.4 0.3 0.2 0.5 0.3

Vince

Trends.....
 

Does the trend in wear metals (Sn/Fe/Cr/Pb etc.) concern you?

Even when new and breaking in, the lead (usually from bearings) was much lower.... :eek:

S

This is a powerful tool for fleet management of trucks - has saved millions in the cost of things like replacement engines.

It must be hard to do this sort of analysis on a car like the RX-8 where the oil is actually consumed by the engine at rates much higher than most petrol engines. My Mazda 6 never used oil between services, but the 8 has already consumed 25% of 1.7litres in 2,500kms.. It would be interesting to compare these numbers with another 9 cars..

Thanks for sharing the data with us - good information...

Interesting info, but has each oil change been at the exact same mileage? has the same brand/grade of gasoline been used? I would think these would have an impact on results.

The mileage has varied between oil changes, to answer your question.

IF there is any wear on the rotor housings, there is no sign of any issues.

Appreciate your willingness to do this Vince.

"Miles on Oil 1250 1764 1500 1500 3000 4000 6581 4400"

First four reading were with less then 1800 miles on the oil. The last three were with 4000 or more miles on the oil. That puts the readings in a better perspective.

It also looks like Redline might have re-blended looking at the:
Moly 480 471 578 599 586 556 574 750
Calcium 1724 2421 2565 2841 2906 3394 2698 3160
Phosphorous 850 1015 1084 1077 1091 1222 1183 1419
The last oil was from a new case.

Vince

Or since the sample was the longest ran without added oil changed the mix a bit.

Vince

Did you go back in time? :D

All better!

Vince

Is there that much salt in the iron?

Where is the salt and calcium comming from?

I think the sodium could be from antifreeze or the oil cooking down. The FE is more than likely wear.

Vince

Ok.

Did you change the air filter / intake at some point? I'm looking at the silicon level.... you seem to have a better filter since after the first change, or the OEM one just got clogged and works better :)

Rotary engines are designed to consume oil, which is squirted through the intake system
by the metering oil pump, this lubricates rotor apex seals and their springs, rotor side seals and their springs.

You cannot compare the use of engine oil with a Mazda 6 or any other piston engine.

Mazda rotary engines should NEVER have synthetic based engine oils in their sumps.

One should only use MINERAL base engine oils.

tell that to rotary tuners like RE-Amemiya

My understanding is that high silicon is normal for breakin period, due to sand-cast components

No changes at all.

Vince