UOA 2017 Subaru Crosstrek, Mobil 1 0-20w, 10k change, 28k on engine

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Recently, did a UOA for my wife's car. Just curious to see if 10k is ok or do shorter. MOLY looks pretty good. The mileage on the report said 24k but it has 28k when the oil was changed. Mobil 1 with the Fram Ultra.

Thanks
 

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It's OK, but, the viscosity is getting low. Reduce oci to 6000 -7500. You could run a thicker 0w-20 like PUP 0w-20. .02
 
28K. Shouldn’t most engines be broken in by then?
Just re-read that, the report says 24:
Screen Shot 2022-11-07 at 4.04.08 PM.png


but he's saying it has 28K. Doesn't really have any impact on this discussion.

No, many engines shed break-in material for quite a while. You'll only know when it is broken-in when you are doing consecutive UOA's (trending) and you see everything settle, and at that point you know what is "normal" for that piece of equipment.

Edit:
Also note that it's a 2017, so this is some pretty low mileage per year being accumulated, so break-in is really being drawn-out. Would be interesting to know how many oil changes it has had, if the 10K is normal, this is likely only the 2nd or 3rd oil change, which would explain the silicon still being leached from sealants.
 
The silicon is a bit high but that could be leaching from sealant still. The wear metals are unremarkable, nothing worth noting there. The 380°F flashpoint and low KV100 indicates a good bit of fuel, definitely more than a "trace". Blackstone's measurement of fuel is a bit rudimentary so I don't trust that result.

I would probably shorten it to 7,500 miles just based on the fuel. Next time, use a better lab. Polaris uses GC for fuel which is much more accurate. They also include TBN and oxidation at no extra charge. Wix kits are easy to find <$20 and also include TBN.
 
Wix kits are easy to find
Not anymore - price has increased significantly. The best deal, for now, is to buy 10-packs from Polaris.

 
Double digit and bold face wear metals. I’d change it out much sooner.
I would have done all the up-to-current OCIs at factory recommended 6k, and the bold numbers would likely be at or below the universal numbers.

Once that happened and everything was kosher (including viscosity) I would then start creeping up in probably 2-3k mi additional increments until viscosity or TBN/TAN showed the oil was at its operational limits.

Then if I wanted to keep stretching OCIs after that, I’d move to a more robust oil like HPL and restart the UOA process with a dipstick tube sample at the same mileage as the shelf oil went out of spec, and go from there.
 
Not anymore - price has increased significantly. The best deal, for now, is to buy 10-packs from Polaris.


Hold on one sec... trying to get my foot out of my mouth...


I didn't realize they'd gone up. The last time I bought any was over a year ago and think I paid $18/ea. Oh well, Polaris it is. I like them better anyway.
 
Thanks fellas for all of the input. I was hoping that I could do the 10k oil change like my Tacoma but I'll shorten it to 7500 next time. I'm surprised to see a modern engine like this that can't do 10k oil change.

Probably should have blacked out the email and phone. She has not put a ton of mileage on this car.
 
Thanks fellas for all of the input. I was hoping that I could do the 10k oil change like my Tacoma but I'll shorten it to 7500 next time. I'm surprised to see a modern engine like this that can't do 10k oil change.

Probably should have blacked out the email and phone. She has not put a ton of mileage on this car.
How many oil changes has it had?

And yeah, if it were driven more, you could probably go further, the issue is the lack of driving, which is likely a contributor/driving factor on the fuel dilution.
 
Thanks fellas for all of the input. I was hoping that I could do the 10k oil change like my Tacoma but I'll shorten it to 7500 next time. I'm surprised to see a modern engine like this that can't do 10k oil change.

Probably should have blacked out the email and phone. She has not put a ton of mileage on this car.
It’s not necessarily the engine’s fault. There are oils that meet the spec, and there are oils that meet your required spec but also more stringent ones that require a better overall package. I don’t have anything against Mobil 1, but maybe try another brand if you’re looking for 10k… a slightly thicker starting point oil may be all you need (or maybe even Mobil 1 EP/ESP?)
 
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