GC 0W30, Subaru Forester XT, 5,930 miles

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First column is current, second column is M1 5W30 w/5,774 miles on the oil.

Equipment make: Subaru
Equipment model: 2.5L Turbo
Oil use interval: 5,930 miles
Oil type & Grade: Castrol Syntec 0W30
Make-up oil added: 0
Miles on unit: 21,930
Air filter: Amsoil
Oil filter: OEM

Aluminum 4 6
Chromium 1 1
Iron 10 15
Copper 6 20
Lead 2 2
Tin 0 0
Molybdenum 12 63
Nickel 1 0
Maganese 0 0
Silver 0 0
Titanium 0 0
Potassium 0 3
Boron 14 115
Silicon 15 18
Sodium 2 6
Calcium 2582 3394
Magnesium 106 10
Phosphorous 680 764
Zinc 818 904
Barium 0 1

Properties
SUS Viscosity @ 210F: 64.8
Flashpoint: 365F [>385]
Fuel %: 1.0 [ Antifreeze: 0 [0]
Water: 0 [ Insolubules: .4 [
Dennis: Nice improvement. You can see your engine maturing in wear with this sample. Most metals have settled down, though iron and copper are still a little above average. They should drop more in the next sample. We did find a little bit of fuel dilution, which is common in engines that see a lot of city driving and/or idling. We don’t consider it a problem until it reads above 2.0%. No other contaminants present, and the viscosity was normal. The fuel isn’t hurting anything. Looks great!
..
This was my first GC UOA. I'll be switching to an OEM air filter soon. I think I might not be getting seal with the Amsoil [plus it's noisier now that I have an aluminum skidplate].

I'm guessing that fuel dilution is due to the fact that it was winter and I drive five miles each way weekdays. I probably didn't "push it" as often as I would've liked [no track, strip or auto-x]. It looks like the additives and viscosity held up "ok" despite the dilution, right? No make-up oil added, although it was about 1/2 quart low right before I sampled it.

Haven't decided on what to use next [GC, M1 10W30 or 0W40]. May push it a little harder during the summer and will do some light off-roading [beach, etc]. Also drive to SC during July.

Comments/advice welcome.
smile.gif


-Dennis
 
Well we are talking different conditions..Your vehicle is more broken in and the vehicle was operated on worse conditions. Probably on balance there isn't a lot of difference between these oils. But probably the GC might be a better choice.
 
I just bought a 2005 Forester XT but haven't put on enough miles for the first oil change. I may get to 1,000 but I doubt it. The choices I have in inventory are Valv durablend 5W30, Maxlife 10W30 and 5W30, and Maxlife syn 5W30. (All free from rebates) I face the terrible decision of using one or buying three more qts of GC, have only 2.
Your UAO is pulling me toward GC but what am I going to do with all that Valvoline?
 
quote:

Originally posted by SSDude:
Why so few miles on the GC?
dunno.gif


I was too anxious.
smile.gif
I also wanted similar mileage to the M1 (although M1 was summer and GC was winter).
 
If you look at UOA's from all the new 2.5 turbo Subee motors, you will see wear metals (especially iron and copper) are elevated until close to 30,000 miles. We can draw the loose conclusion that the motor takes that long to break in. If that's true, then your interval on the GC from about 16k miles to almost 22k miles should be during the break in, and metals should be high. They are not high, and two possibilities exist; one, your motor broke in quicker than most, or two, the motor likes GC a lot.
In a turbocharged car, even though GC and most synthetics are very good, I would still not push the drain interval to it's limit. Until I know what's going on inside the turbo, 5900 miles is plenty long.
 
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