Oil for 04 Subaru EJ251?

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Nov 13, 2011
Bozeman, MT, USA
I've been reading through threads for the last hour or two about different types of oil and can't seem to come to a reasonable conclusion for oil to run in my 04 Subaru Legacy (NA 2.5). I'm a Ford guy and I'm used to just putting whatever is cheap in because they'll run on anything you can fit down the fill tube, but in the last few years I've converted to running Mobil 1 EP in everything. Everyone seems to say something different about each oil, I just want the "best" oil for my engine that I can find locally. I think I've pretty well narrowed it down to: Pennzoil Ultra (some people seem to prefer Platinum instead?) Red Line Mobil 1 EP Any particular reason to choose one over any of the others? I've been running Castrol GTX and now the SynTec blend of it for a few changes now for $ reasons but I want to go back to synthetic. I'm sure when my engine finally goes to the lube shop in the sky there won't be any "well if you had used this other oil you'd have another 10k left in this engine" but I'm just a paranoid/obsessive compulsive freak that likes to keep everything well maintained. Driving habits are very mixed, I drive about 11 miles to and from class and work every day @ 60 MPH (pretty easy on an engine). Temperatures drop as low as -30 in the nasty part of winter and will reach about 100 in the peak of August heat, I like to put my foot down on the backroads sometimes but generally I take it fairly easy on the engine. Drain intervals I don't care about, when I was running M1 EP I was changing at 3k because I didn't know better, if I can get 5k-8k that's great. I've already got an oil test kit waiting for my oil change to see how the Castrol is holding up and will test the Synthetic around 4k-5k to see how my engine takes to it. One last thing (sorry about the length sleep): This car is parked almost all Summer, only sees maybe 1,000 miles unless I go on a road trip. Not sure what effect that will have on the oil.
First off, welcome to BITOG!!!! Now, on to your question. I used to think that an NA Subaru was better off with a thicker oil, so I used GC for quite a few miles. It then dawned on me that their were many good UOAs of NA Subarus using fairly thin 5W-30 oils. I have Synpower 5W-30 in our 2.5 NA at the moment, and PP 5W-30 in our 2.2 NA. Of the oils you've listed, I'd select Ultra or PP. Both have held up well in a number of applications as shown in the UOA forum here. Red Line is very expensive and is overkill for your application, while there is no reason to use M1 EP for a 5K OCI. QSUD would also be a good choice. You could also continue with conventional oil, for which I would recommend either PYB or QSGB. I'd use syn myself, especially since you see real cold each winter. OT, I've driven through your area on the way to Spokane. Pretty remote and unpopulated! Cattle guards on the interstate on and off ramps?
Thanks for the welcome! Our local Wal-Mart has the jugs of Ultra and Platinum, just down the road from CarQuest so oil changes are nice and easy. I don't mind a little overkill, but I see what you mean. If I stretched my OCI to 8k would M1 EP be a good choice? It's not that much more expensive than the Ultra and 3k miles is a lot! Yeah it's pretty unpopulated until certain times of day when everyone is going home. Doesn't help that nobody here knows what a speed limit is, 15 MPH under the limit makes for a little extra traffic. The cattle guards are pretty funny, though! People are going to read this and think "they must be joking" but it's true. Thanks for the tips!
Ultra has shown to hold up well on 8K drains. Check the UOA forum. PP does well on longish drains as well. Once again, the UOA forum is your friend. That said, nothing at all wrong with any M1. OT again, have you ever lived in one of the more crowded states? In either SD or MT, my speed was based upon how fast I felt like driving. Here, speed is mainly limited by traffic, which is remarkably thick on the interstates, with plenty of trucks to clog things up. I thought the cattle gaurds were a hoot. Open range is something we don't have here.
Yeah I've driven in L.A. rush hour traffic, not fun. Despite all the traffic down there it does flow much better, people are more attentive than they are here, and generally less stupid. Open range is cool but when you come around a corner in the mountains at 45 and see a cow 10 feet away you could crush a soda can with your butt, serious crimpage happens laugh I'll check the UOA forum, didn't actually notice it at first (I thought they were listed in this one and I just couldn't find them).
I would say Pennzoil or Quaker State* conventional would do 5000 easy. Pennzoil Platinum/Ultra or Quaker State Ultimate Durability** should be able to do 7500 easily. * I list these because 1: I am a fan of SOPUS products and 2: the engine in my 2003 Outback runs quieter and smoother (less piston slap and/or classic Subaru ticking) on those two oils (perhaps the high moly content?) on them than on Castrol, Valvoline, or Mobil oils. ** I list these because they are hard to beat price wise. QSUD is usually found for $20ish at WalMart.
What fdcg said! N/A Subes are easy on oil so you can run anything you want! I usually run Pennzoil High Mileage in a 2000 2.5RS at 5-6k mile intervals, but recently switched to Ultra. -Dennis
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