Mobil 1 5W-30/4546 miles/2007 Mazdaspeed3

[Doug Hillary]

Hi,
RI_RS4 - You said:
"I disagree with your opinion, and I've stated the reason. You are quite wrong about oil analysis being an "inaccurate science" at best."

I accept that you have a different opinion! As for the majority of UOAs posted on BITOG being an "inaccurate science at best" - I will stick with mine!

MCompact - Thank you for posting further UOA data - it certainly makes it all the more meaningful

 

[RI_RS4]

Mcompact,

When did you change your air filter, and what type are you using?

 

[MCompact]

Originally Posted By: RI_RS4
Mcompact,

When did you change your air filter, and what type are you using?


The car has the stock airbox and uses a Mazda filter element. The element was changed at 14,771 miles. I also noticed the sharp decline in the silicon numbers, but as you can see, the drop off did not occur until the second OCI after the filter element was changed. Assuming I keep the car, I plan to fit a Mazdaspeed Cold Air Intake, which uses an AEM Dryflow conical filter.

 

[RI_RS4]

Based on that, I'd say you ingested a lot of crud during your track event, under high vacuum, which is not unusual. I'd keep an eye out for the filter and seals in the intake.

 

[BeerLube]

Originally Posted By: MCompact
Originally Posted By: RI_RS4
Mcompact,

When did you change your air filter, and what type are you using?


The car has the stock airbox and uses a Mazda filter element. The element was changed at 14,771 miles. I also noticed the sharp decline in the silicon numbers, but as you can see, the drop off did not occur until the second OCI after the filter element was changed. Assuming I keep the car, I plan to fit a Mazdaspeed Cold Air Intake, which uses an AEM Dryflow conical filter.


I highly recommend the MSCAI. Interestingly, I just cleaned it for the first time last weekend, before which I had probably 25k miles since installation, and during which I've sampled every UOA I've posted here...all with seemingly good filtration.

It floored me at just how terribly dirty the media was, considering what I feel is a generally benign driving environment, i.e. lots of freeway miles in open, clear areas. It really woke up the car after cleaning, almost as if I had just upgraded from stock again. Enough that a new BMW E90 M3 wasn't really able to pull on me from ~60-120 during our several dozen miles of cat/mouse; what a fun time that was! Admittedly, he did have two or three passengers, but still not at all what I was expecting!

 

[MCompact]

Originally Posted By: BeerLube
I highly recommend the MSCAI. Interestingly, I just cleaned it for the first time last weekend, before which I had probably 25k miles since installation, and during which I've sampled every UOA I've posted here...all with seemingly good filtration.

It floored me at just how terribly dirty the media was, considering what I feel is a generally benign driving environment, i.e. lots of freeway miles in open, clear areas. It really woke up the car after cleaning, almost as if I had just upgraded from stock again. Enough that a new BMW E90 M3 wasn't really able to pull on me from ~60-120 during our several dozen miles of cat/mouse; what a fun time that was! Admittedly, he did have two or three passengers, but still not at all what I was expecting!


My MS CAI is still in a box in the basement; I'm not going to install it unless I decide to keep the car. If I do install it I'm buying an extra filter so I can quickly swap the clean one in and not have to rush cleaning the dirty filter. I bought one of the last original CAIs just before Mazda issued the stop sale order. I also bought an AEM air straightener, though it now seems that AEM and Mazda disagree on how the straightener should be oriented relative to the MAF...

 

[cheetahdriver]

Originally Posted By: RI_RS4
There is a widely held belief that the highest engine wear occurs right at an oil change. This is a misconception, because wear metal concentrations have been contaminated by left over oil from the change. Once this residual concentration is subtracted out of the analysis results, the early wear rate after oil change is close to the average wear rate. Most people do not take to time to determine this, but actually it's quite easy , using oil analysis, to determine what the residual oil volume is, and perform the proper corrections to the analysis record.


umm...so you total disagree with SAE paper number 2007-01-4133???

 

[JAG]

Originally Posted By: cheetahdriver
...SAE paper number 2007-01-4133

I thought I'd post the abstract:
http://www.digitalcar.org/technical/papers/2007-01-4133
Quote:
The Effect of Engine Oil Drain Interval on Valvetrain Friction and Wear
Abstract:
Engine oils are subjected to a series of industry standard engine dynamometer tests to measure their wear protection capability, sludge and varnish formation tendencies, and fuel efficiency among several other performance attributes before they are approved for use in customer engines. However, these performance attributes are measured at the end of tests and therefore, do not provide any information on how the properties have changed during the tests. In one of our previous studies it was observed that engine oil samples collected from fleet vehicles after 12,000 mile drain interval showed 10-15% lower friction and more importantly, an order of magnitude lower wear rate than those of fresh oils. It was also observed that the composition of the tribochemical films formed was quite different on the surface tested with the drain oils from those formed with fresh oils. The objective of this investigation is to demonstrate how the friction and wear performance changed with oil drain intervals. A fleet of three vehicles was run in Las Vegas and oil samples were collected at various drain intervals from 3,000 miles to 15,000 miles. As in the previous study, the results showed that the aged engine oils provide lower friction and much improved wear protection capability. These improvements were observed as early as the 3,000 mile drain interval and continued to the 15,000 mile drain interval. The composition of tribochemical films formed on the surface with the 3,000 mile drain interval is similar to that formed with the 12,000 mile drain interval as seen before. These findings could be an enabler for achieving longer drain interval although several other factors must to be considered.