My wife's daily grocery getter. Some short trip, some highway, nothing unusual. Used the Subaru oil because she got a coupon for a cheap synthetic oil change at the stealership. Blue Subaru oil filter and OEM air filter.
2020 Subaru Outback 2.4L XT, 0W-20 Subaru Synthetic, 6023 miles
- Thread starter garyb80
- Start date
Air filter was changed about a year ago. The high silicon could be from a dust storm that we drove through in West Texas a few months ago.
As Javier pointed out the silicon is higher than what you'd typically see but the universal averages shows it is perfectly normal for these engines so no worries there. The wife must have perfect driving b/c there is virtually little wear going on in this 6k interval. Keep it up!
The universal averages may include cars with low mileage that have very high Si during break-in, which would push the average up. UOAs on the factory fill on Subarus are typically 200-500 ppm. I'm not sure if Blackstone includes these in their averages or not.
At 50k miles I'd expect Si to be at or below the universal average. It would be worth the effort to at least check the airbox. The airboxes on these cars are known to sometimes have filter sealing issues. I've experienced this with aftermarket filters on my Subaru, but not with OEM.
If the Si is from dust, it could just be due to the new air filter. New filters have especially poor efficiency in the 0-5 micron range. They become much more efficient in this range as they load up with some dust. Particles this small don't cause a lot of wear, but will show up in a UOA.
Looks good and a good oci for you.
Good Morning Garyb80,
Excellent report . . . you're doing everything right! Thank you for sharing.
My long term beliefs that heavier oil produces less wear than lighter oil has been proven to be incorrect in Automobile engines. I used Mobil 1 oil in my '22 Forester and '18 Forester Turbo. I will be going back 0w20 IN BOTH EVEN THOUGH 5w-30 IS RECOMMENDED FOR MY '18.
Hardly. Changed my mind in the last 6 months.Proven by only one Blackstone UOA? I wonder why Subaru Japan allows up to Euro 0W-30 in the FA24DIT and even 5W-40 in the
FA20DIT?
Japan allows it bc its an engineering fact that it won't hurt...according to the Three factor journal bearing graphs.
People post things they don't understand and make completely unwarranted conclusions from them all the time. This is no exception.Proven by only one Blackstone UOA? I wonder why Subaru Japan allows up to Euro 0W-30 in the FA24DIT and even 5W-40 in the
FA20DIT?
Never mind. Not worth the effort.
If you are referring to me (which you may not be
) You (should) know. It takes me a while to change my opinions. 
Yes, there have been a few times I’ve worked with the owner, Ryan, on gathering several hundred samples for a given engine, and he told me that they filter out “known” failures and severe outliers. When I got the raw data I did a similar thing, and excluded any data points that were >3 sigma from the centerline of the data.
My UOA's
