M1EP - 5W30 - 3500mi - 04 Toyota Prius HYB (w/PCs)

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Apr 5, 2004
Pensacola & Vero Beach FL
OK, before everyone piles on because I used EP for only 3500 miles -- hold on -- this was essentially a test run. I bought the car with only 15k miles about 1.5 months ago, and promptly replaced the clean looking mystery oil (presumably dealer bulk natural HC 5w-30) with this fill of M1EP, dosed heavily (roughly 2x normal) with LC20. The car came with a new-looking OEM filter, which I left in place for about 1/3 of this run, and then swapped it for a new K&N. This engine is spec for 3.9 qts for a full (with filter) change, so undoubtedly, there is some of the old natural HC oil left in this fill.

The engine certainly wasn’t dirty looking (or I’d never have accepted it in the first place), but it did have what appeared to be the very beginnings of varnish forming in the oil filler.

I decided to give the engine what I believed to be the most robust, OTC available, rinse out and purge that I could, short of an ARX cleaning (which is now underway, started before I saw these results). I chose EP for two reasons (the validity of which are certainly open to question…). First, I presume it has a good TBN reserve just in case the engine actually had some really stale stuff in it (who knows how long that fill really was in there). Second, it is one of the lowest vis 5w-30s in the M1 line (though they’ve seemingly all migrated to around 11 cSt from around 10 where they were a year ago and earlier).

I also run FP60 in the gas, at the standard dosage. On the last fill of gas before I drew this sample, I added a full bottle of Redline SI-1 fuel injector/system cleaner.

Despite all my “clean up the new used car” compulsive stuff, I hasten to add that the engine runs well with no symptoms of difficulty at all. One could certainly legitimately question why I’ve bothered with the cleaning efforts, including the now-underway experimental ARX treatment.

In summary, I'm pretty pleased with the resulst overall, but I am wondering about: 1) the Sodium, 2) the insolubles (which seem high for such a short run), and 3) the marginal flashpoint. All thoughts and comments welcome.

OK, here’s the data:

Element This Last 2nd to Last Universal

Sample Sample Sample Averages

Aluminum 2 - - 3

Chromium 0 - - 0

Iron 3 - - 9

Copper 0 - - 1

Lead 0 - - 0

Tin 0 - - 0

Moly 66 - - 57

Nickel 0 - - 0

Manganese 0 - - 1

Silver 0 - - 0

Titanium 0 - - 0

Potassium 1 - - 1

Boron 51 - - 63

Silicon 5 - - 12

Sodium 49* - - 10

Calcium 1752 - - 2391

Magnesium 12 - - 11

Phosphorus 545 - - 636

Zinc 639 - - 728

Barium 0 - - 0

- - -

TBN 5.7


Test : Vis Flash Fuel AFZ H2O INSOL

@210F Deg F % % % %


Shd Be: 56-63 >365


This: 58.4 365 -TR- -?- 0 0.3 (!?)




2 microns or less = 959

5 microns or less = 355

10 microns or less = 98

15 microns or less = 38

25 microns or less = 9

50 microns or less = 0

100 microns or less = 0

ISO Code = 16/12, “clean”

* = Flagged by Blackstone as Elevated

Looks excellent to me! The sodium is surely from previous oil as lots of them now use it as an additive. I have personal experience in how long it takes to get the stuff out after using an oil without it. Three 6000 mile changes before it went back to normal.

And you are doing an AutoRx for what reason?

Obsessive carpet bombing -- or something like that... As I've mentioned, the oil filler area looked as if it had the very beginnings of some varnish in it, so I decided to try it, pretty much just to see what would happen. I think at this point, I can pretty much reclassify the current ARX dose as an "experiment for amusement". Hey, it's your fault BITOG -- look what you've done to me!

One more thing: anyone got any ideas about the flashpoint? The Na and insols sort of make sense in context, but why should the flashpoint have dropped to the minimum acceptable in such a short time in an otherwise seemingly unstressed oil?

Thanks for your comments.
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The low flashpoint is due to all the LC20 you added to the crankcase....Sodium is left over from the previous oil (Mobil Clean 5000?).

Total solids does look high, but could be residue loosened up from the oil pan.


Thanks for the feedback -- gee, I think I should have recognized the LC20 effect on flash...
As I noted in above, I'm pretty much just having fun at this point. The current ARX spiked fill (which happens to be MC5k 5w-30; I have no idea what was in before) will hit 1500 miles this evening, and get drained this weekend. I'm contemplating sending a bottle of it off to the lab just to see what ARX treated oil looks like after the clean phase.

Thanks again for the input on what must be one of our most pointless UOAs to date.
OTOH, considering some of the other ridiculous things people spend money on for fun, I don't feel so bad.
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