2019 Subaru Ascent - Castrol Synthetic 0W-20 - 3,409 Mi OCI

2k miles over on one change causes damage? I would take this as a cheap warning that this is a stealership and they should go else where from now on. With a regular maintenance record moving forward any dealership will take it on a trade in without an issue. Even if there is an engine issue related to oil in the warranty period, another dealership could decide to ignore the one slip up as inconsequential.
 
2k miles over on one change causes damage? I would take this as a cheap warning that this is a stealership and they should go else where from now on. With a regular maintenance record moving forward any dealership will take it on a trade in without an issue. Even if there is an engine issue related to oil in the warranty period, another dealership could decide to ignore the one slip up as inconsequential.
Service schedule is 6/6k for normal, 3/3k for severe.
 
2k miles over on one change causes damage? I would take this as a cheap warning that this is a stealership and they should go else where from now on. With a regular maintenance record moving forward any dealership will take it on a trade in without an issue. Even if there is an engine issue related to oil in the warranty period, another dealership could decide to ignore the one slip up as inconsequential.
Based on this UOA, 12k OCI definitely had excessive oxidation.
 
The purpose of UOA is not the state of engine, but oil. There are engines on death bed that will provide good “wear numbers.”

If the previous oil run caused excessive wear, I would expect at least SOME elevated residual wear metals to show up as they are washing out. If everything looks normal, would you continue to stress a one time extended synthetic oil run or you’d sleep easy knowing that the engine is currently just fine…? 🤔🤷🏻‍♂️
 
If the previous oil run caused excessive wear, I would expect at least SOME elevated residual wear metals to show up as they are washing out. If everything looks normal, would you continue to stress a one time extended synthetic oil run or you’d sleep easy knowing that the engine is currently just fine…? 🤔🤷🏻‍♂️

It's funny how much paranoia has been created online about the following:

1. Subaru oil filter bypass spec and how much the OEM oil filter sucks (cardboard endcaps!!!)
2. Subaru's history of oil consumption issues
3. Subaru's history of head gasket issues
4. Known issues with TGDI engines like carbon buildup, fuel dilution, etc
5. Thin 0w20 oil in a TURBO GDI engine for 12,000 miles

I could go on but for the amount of complaining I have heard on these subjects over the past decade at the very least it just amazes me to see people acting like a 12000 mile oil change interval, on an engine that should only be doing a 6000 mile OCI at most, will not be problematic is an absurdity. No big deal, nothing at all to worry about, nothing to see here, move along, move along...

Watch this video below, there is nothing wrong with this whatsoever!




I feel like there are a lot of people who have lost their complaining privileges after this 💩 and I am going to start referring people to this thread when I see whining about these subjects in the future because obviously there is nothing to worry about.
 
If the previous oil run caused excessive wear, I would expect at least SOME elevated residual wear metals to show up as they are washing out. If everything looks normal, would you continue to stress a one time extended synthetic oil run or you’d sleep easy knowing that the engine is currently just fine…? 🤔🤷🏻‍♂️
Again, UOA is not designed for that purpose. To know that you need trend. But, based on state of this oil, I would expect some oxidation deposits. Run Mobil1 0W40FS for 3k, dump it and do regular changes after that.
 
If the previous oil run caused excessive wear, I would expect at least SOME elevated residual wear metals to show up as they are washing out. If everything looks normal, would you continue to stress a one time extended synthetic oil run or you’d sleep easy knowing that the engine is currently just fine…? 🤔🤷🏻‍♂️
This oil was ran from 35,042 to 38,451 for 3,409 miles. OP said the extended interval was from 20-32K.

So a different fill was already ran from 32K-35,042. Any residual metals were probably flushed out.
 
This oil was ran from 35,042 to 38,451 for 3,409 miles. OP said the extended interval was from 20-32K.

So a different fill was already ran from 32K-35,042. Any residual metals were probably flushed out.
So do you think there's actually significant engine damage from the 12k OCI? They do have a oil heat exchanger with the cooling system so the oil is running at a consistent temperature at least.
Sure its not ideal, and running that interval all the time would shorten the engine life, but from what I can find online Subaru europe requires 15k km or 9300 mile oil changes, but that is unlikely to be 0W20 in a turbo engine either...
 
So do you think there's actually significant engine damage from the 12k OCI? They do have a oil heat exchanger with the cooling system so the oil is running at a consistent temperature at least.
Sure its not ideal, and running that interval all the time would shorten the engine life, but from what I can find online Subaru europe requires 15k km or 9300 mile oil changes, but that is unlikely to be 0W20 in a turbo engine either...
Subaru in 2.0T engine in Outback in Europe recommends ACEA A3 oils. Castrol recommends good ole 0W30 or 0W40.
 
I would go to a different dealer just based on them trying to charge to do diagnostics to determine engine damage as well as trying to get another dealer to fix the leaking oil pan. But it's possible that there could be an issue with the Powertrain Warranty since these long OCI's are now part of the car's record regardless of which dealer you go to. And if it ever comes to fighting that, it will get very expensive.

Yes, this is only one uoa and low uoa wear numbers don't really prove much. Even a dozen good uoa's do not prove that there is no engine damage. I blew a turbo because I extended my OCI beyond SoA's recommendation (based on good uoa's). But I didn't attempt to fight it because I wouldn't have had a case.

I think it's still probably worth showing the uoa to the dealer and even asking them to log in her file that a used oil analysis was performed and the results were good.
 
This dealership is BS. Based on this recent UOA, your engine isn't shedding metal at a rapid rate. That's enough to determine if there has been damage, its behind you. Will you make it to 300K? Maybe not, but I seriously doubt this will make a difference in terms of your ownership/warranty experience. I can almost guarantee you that long OCI will not cause any issues, if any, during your powertrain warranty. If you're that worried, "generate" some receipts.
 
All true, and yes I know trends are the most important facet of UOAs, but it isn't as if wear metals are an arbitrary item.
 
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I can't imagine that any significant damage was done. Did the dealer notify her of the historic, but non-recall worthy, problem with the wing flap actuator on the hyperdrive? A silly dealer story. My 2020 Outback came with a 3 year / 36,000 mile warranty on wear items, including wipers, brake pads and clutch linings. The dealer said that they would only cover one wiper blade change per vehicle. I replace my wiper blades when performance decreases. That happens someplace between 6 months and one year. I'm so glad the wiper blades are of historic quality, while the motors are self destructive crap. P.S. I got in touch with Subaru NA, who politely responded that the wiper blades could be replaced under warranty as needed.
 
These extended drain intervals should be seen as a best case scenario and do not apply to every single engine in every single circumstance for every single vehicle. You can read on any container of motor oil and see that the oil manufacturers recommend following the auto manufacturers' oil change recommendations.

The engine in the Subaru Ascent (FA24F TGDI) in its short history is known as an engine that is incredibly hard on oil (based on UOA data) and Subaru's normal 6000 mile oil change interval should be seen as a maximum interval for that engine. If you read the owners manual the majority of owners will likely fall under the 3000 mile severe service interval, it's not necessarily about what engine oil you use but rather has to do with the engine you are using it in.

Furthermore Subaru also specifies that oil consumption can be expected in these engines in the owners manual and I can only imagine what may have happened if the interval was 12,000 miles instead of 3000 to 6000 miles as recommended. Another factor is the oil filter, the Subaru OEM oil filter is not good for much more than 6000 miles of usage per Subaru so chances are that the engine was seeing unfiltered bypass oil on a regular basis. Subaru has also issued a TSB for carbon buildup for these engines in recent times under normal usage circumstances, running extended oil change intervals is only going to further contribute to that known issue.

Moral of the story is that I would have to agree with the dealership that running that specific vehicle for 12,000 miles between oil changes is problematic at the very least and quite likely did cause serious damage. Doing this likely voided any warranty on that vehicle as well.
I had a BMW 3 series with a turbo charged motor that called for a 10,000 mile oil change. I had the dealer do it when recommended by the OLM. No self destruction. I currently have a 2020 outback xt limited. I would appreciate more info, i.e. the UOA data to which you refer. This one was not indicative of an engine that was about to self destruct. I do mine at 6,000 miles with full synthetic, just in case my dealer is reading this. As for the warranty, push comes to shove, Subaru would have to prove the extended OCI was the cause of any problems if it was my car. I would like to have seen the metal flakes reported. I was in a dealer, not subaru, listening to a service rep, not the mechanic, load a poor guy with around $1,000 of total bs. I was looking shocked and the rep kept looking at me like, don't rain on my parade. I didn't, but still feel a little guilty about it.
 
I had a BMW 3 series with a turbo charged motor that called for a 10,000 mile oil change. I had the dealer do it when recommended by the OLM. No self destruction. I currently have a 2020 outback xt limited. I would appreciate more info, i.e. the UOA data to which you refer. This one was not indicative of an engine that was about to self destruct. I do mine at 6,000 miles with full synthetic, just in case my dealer is reading this. As for the warranty, push comes to shove, Subaru would have to prove the extended OCI was the cause of any problems if it was my car. I would like to have seen the metal flakes reported. I was in a dealer, not subaru, listening to a service rep, not the mechanic, load a poor guy with around $1,000 of total bs. I was looking shocked and the rep kept looking at me like, don't rain on my parade. I didn't, but still feel a little guilty about it.
Have a look on subaruoutback.org and there is a uoa sticky in the oil forum there. And for uoa's on the older FA20DIT, do a search on nasioc.com and subaruforester.org. Different engine, but similar uoa results.

Running BMW spec oil at 10,000 miles is not the same as running 0W-20 in a turbocharged Subaru.
 
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