6 Months and 6362 Miles on '00 Subaru OBW

['00obw]

Vehicle is a base model 2000 Subaru Outback Wagon with automatic transmission and 33750 miles.

This OCI history:
24Nov'03, changed oil and oil filter (OEM) with 3 1/2qts. Mobil 1 SS 10w30, 1qt. Amsoil S3K 5w30 and 4oz. Auto-RX...Used up all my stock of oil.
27Nov'03, changed air filter with OEM.
2Apr'04, at 3933 oil miles, changed oil filter (OEM) and allowing for the old and new filter drained enough oil to add 1qt. Mobil T&SUV 5w40...Since this was a winter run, I decided to change OF and try to replensish the additive package.
1May'04 added 4oz. LC...Just got it.
Used 2oz Lucas UCL in gas about once a month.
No other make-up added and still in service.

Oil analysis by OAI/CTC. 1st number is previous UOA and 2nd number is this sample. Sample dates are 17Nov'03 (~7 1/2months) and 25May'04.

code:

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Miles on Samples 8366 6362



Fe Iron 11 12

Cr Chromium 1 2

Pb Lead 9 7

Cu Copper 12 5

Sn Tin 0 6

Al Aluminum 5 7

Ni Nickle 0 0

Ag Silver 0 0

Si Silicon 16 11

B Boron 75 88

Na Sodium 16 22

Mg Magnesium 32 108

Ca Calcium 2928 2709

Ba Barium 0 0

P Phosphorus 1067 1067

Zn Zinc 1277 1238

Mo Molybdenum 48 44

Ti Titanium 0 0

V Vanadium 0 0

K Potassium 0 0

Fuel %Vol
Vis@40C na na

Vis@100C 11.14 11.06

Water % 0 0

Soots/Solids na na

Glycol neg neg

TBN 5.08 3.28

Oxid 33 30

Nitr 19 18

Change yes no

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Had a mild winter, lows never dropped below 40*F. Drove about 65/35 city/hiway miles. Althou this UOA compares favorably with the previous, I have concerns with tin and sodium. The previous 3 UOA show 0 tin and sodium at 16,0 and 0. What can cause these 2 to jump? TBN has dropped a bit but oil is still in 30wt grade.

I hoped to run this until the 1st week of August but with TBN at 3.28, I don't think it would make it by it-self. So I was thinking about draining a quart and adding a HD oil.

As always your comments and recommendation are greatly welcomed....bgin

 

['00obw]

VVK wrote:

quote:

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I bet you would get far lower wear rates it you used a non-synthetic 10W-30 (e.g., Castrol GTX) for about 5k miles or a quality blend (e.g., Castrol GTX Blend) for 8k miles.

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At my next OCI, I plan to use a syn-blend for 4 months, regardless of miles. Trying to get this to Aug so I'll have OCI's of Aug-Nov, Dec-Mar, and Apr-Jul.

Thanks...bgin

 

[vvk]

I bet you would get far lower wear rates it you used a non-synthetic 10W-30 (e.g., Castrol GTX) for about 5k miles or a quality blend (e.g., Castrol GTX Blend) for 8k miles.

These Subaru engines do best when left pretty well alone. Just keep it simple...