Originally Posted By: bluesubie
The n/a EJ's are easy on oil but peace of mind is priceless.
I'm actually working my way around to the idea that the 2.5L NAs aren't very easy on oil. They're easy to get good UOAs out of, but that's not exactly the same thing. I've got 5 of the 2.5L NAs (not all owned by me, thank god. Includes close friends who don't want to do anything under their own hoods) that I do 100% of the maintenance on. That's the fleet to which I was alluding earlier. I've worked on all of them for a minimum of 100,000mi each. Several I've rolled off the delivery truck and no one but me has ever touched them and they're now over 150k each. Lots of miles in total. I've got about another 60 or so that I see professionally (I own a Subaru specialty shop). That's just NAs, no turbos in this anecdote. Anyway, the ones that are driven completely grandma-like seem to be mostly ok on just about any oil at up to a 7,500mi OCI. They'll consistently show good UOAs. However, sticking a bore scope into them, you can see definite differences in wear rates to the lower side of the cylinder wall that do correlate pretty well with HTHS. I've sent black-box loggers around with a lot of these people to monitor engine oil temperature and they all consistently see oil temps above 230F for a good portion of their trips even when they're driving very, very gently. Those of us that get on it a bit generally can work up to oil temps well more than 280F. That's pretty [censored] demanding on the oil. The NA cars don't have the oil-to-water heat exchanger that the turbo cars do, and I think they really ought to.
I think the reason that the NA EJ25s have a reputation for being easy on oil is that, if you're driving it like a tree-hugging, duck-squeezing, granola Hippy, they don't do anything that shows up in a UOA. You could get a good UOA out of baby oil under those conditions.
Even an oil on the PQIA's advisory list would be fine for your application.
