Subaru UOA Spreadsheet

[nicrfe1370]

This poor spreadsheet is in need of updating, but the info is still good. Let me know if you have problems accessing it.

http://spreadsheets.google.com/ccc?key=pyN_TwC_S5exEIcwPtRPlBA

It's the UOA's from this site (and one or two others) for all Subaru's I could find. When I stopped updating it I had just gotten enough data to start seeing trends.

 

[harrydog]

Nice work. What trends were you seeing?

 

[nicrfe1370]

Originally Posted By: harrydog
Nice work. What trends were you seeing?


I don't remember exact numbers because I lost some of the charts I made, but generally speaking it appeared that around 5500 miles wear began to increase more rapidly. If I recall it wasn't a big increase, but it was something you'd notice on a line graph.

 

[nicrfe1370]

Originally Posted By: harrydog
Nice work. What trends were you seeing?


Oh yes, and it appeared that new Subaru's didn't fully "break in" until 20-25k miles.

 

[scoobie]

my subaru impreza is just starting to feel broken in at 15,000 miles. the engine has got quieter, and the mileage is slightly better.

 

[Titan]

Quick look: The fuel dilution is higher in Turbos (no surprise), and the highest Silicon readings were in Turbos, although overall, Silicon average wasn't higher than non-turbos. I guess if you have a leak, it's going to show up much more in a turbo (no surprise, again!).

 

[nicrfe1370]

Originally Posted By: scoobie
my subaru impreza is just starting to feel broken in at 15,000 miles. the engine has got quieter, and the mileage is slightly better.


Yeah, the majority of break-in wear seems to occur by about 12k miles, but there does appear to be a small amount of additional break-in wear until about 25k.

 

[webfors]

Interesting stuff.. I have my first UOA coming up in the next month on my new forester. Currently at 12k'ish miles (21k km).

Oh, the lovely snow. I put on 4 Continental Conti Viking 3, and grip is just silly..

 

[nicrfe1370]

Updated.

 

[bulwnkl]

Here's another you can add to the spreadsheet if you wish to. It's a pair of RLI UOAs.
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1244958#Post1244958

 

[nicrfe1370]

Updated again. There are a stupefying number of Subaru UOA's on BITOG alone, I still have about 2.5 years to catch up on to be current.

A note for those of you who have posted Subee UOA's; go back and check all your posts and make sure the reports are still there. Over 10% of threads had the results posted as an image, and the image is gone so the results are gone too. Also, for future reference, please indicate either the specific model of the car or the engine size, plus include all info from the UOA, even if it's zero. If it's not specifically listed, I assume it wasn't tested. Please don't say "all other numbers were zero," I don't know what other elements were tested.

 

[LoneRanger]

This is just phenominal info. Thank you very much for compiling it. My new Forester is still in engine infancy, only 2100 miles on the odo so far. Still trying to decide what oil to run, this will help.

 

[Titan]

Originally Posted By: nicrfe1370
Also, for future reference, please indicate either the specific model of the car or the engine size, plus include all info from the UOA, even if it's zero. If it's not specifically listed, I assume it wasn't tested. Please don't say "all other numbers were zero," I don't know what other elements were tested.

As one of those that posted "all other numbers were zero", mine were standard Blackstone reports, without TBN or TAN. I'm too lazy to go back now and repost them. Whatever is on Blackstone that I didn't enter those are what were zero. B-)

 

[nicrfe1370]

I have very little experience using spreadsheet programs, but I have attempted to do some preliminary analysis of the data in the spreadsheet so far. When I plot the wear metals on a graph (I've tried iron, chromium, and lead so far) versus oil drain interval (miles on oil), and then I have the software install an exponential trend line, the line ends up looking very linear. What I think we might be able to tentatively conclude is that over the span of oil change intervals that we have good data for (up to 8000 miles or even 13500 miles?) wear remains linear and shows no benefit to changing the oil sooner.

Hopefully one of you is a mathematician or statistician and can analyze the data and report back with your findings.

 

[bulwnkl]

Iron wear is fairly linear with miles. Copper wear, though (to give one example), is generally not linear. Copper wear will show its non-linearity best when comparing a UOA set of, say, 1000 miles to 5000 miles. Copper ppm/mile is generally much higher at 1000 miles than 5000.

 

[nicrfe1370]

Originally Posted By: bulwnkl
Iron wear is fairly linear with miles. Copper wear, though (to give one example), is generally not linear. Copper wear will show its non-linearity best when comparing a UOA set of, say, 1000 miles to 5000 miles. Copper ppm/mile is generally much higher at 1000 miles than 5000.


There is something magical that seems to happen at the 5000-5400 mile range. If you ignore trend lines and just sort of eyeball the data, in that range wear metals seem very happy.
The higher ppm/mile number for copper at 1000 miles is certainly curious. The only hypothesis I have to explain that is perhaps after an oil change when you first start the motor, those few seconds of low oil pressure do a little damage.

 

[bulwnkl]

Actually, the copper thing is mainly the result of reaction between the fresh oil (mainly additive package) and the copper.

As to the happy place in wear metals, I agree that it often goes south afterwards. Usually something about the oil is going wrong when you see the trends breaking. For example, perhaps total acids have exceeded total bases by that time.

It is kinda cool to watch the numbers and trends isn't it?

 

[nicrfe1370]

Originally Posted By: bulwnkl

It is kinda cool to watch the numbers and trends isn't it?


You can say that again! I am strangely mesmerized by them.

 

[WolfPlayer]

Here are all of the results from my 2005 STI.

http://www.bescaredracing.com/sti/oil/analysis/

t

 

[nicrfe1370]

Originally Posted By: WolfPlayer
Here are all of the results from my 2005 STI.

http://www.bescaredracing.com/sti/oil/analysis/

t


t,

Yeah, I came across your stuff. One word; awesome! That is an impressive collection, well organized and a pleasure to look through. Thank you for posting the link to your page in case I had missed it. I have about half of your samples in the spreadsheet so far.