use a 30 grade and maybe even a 40 during summer roadtrip season like i used to do until going to a 40 entirely. That engine is hard on the oil. sheared it a lot. i wouldn't be afraid to use an sn plus or sp rated 40 grade either.
I missed this reply, my bad. I'm definitely ok with stepping up one grade to a 30w but I'm reluctant to step up to a 40w, especially this early in the vehicles life. As the get closer to 100k, maybe so. But judging off my use, we won't hit 100k for another 10yrs or so. Our previous car was a 12 Fusion that we sold when we got this in Nov 2020 and it had 85k-ish when we sold it and our driving habits really haven't changed much.
I don't think this engine is used outside of North America but I do recall the FA20DIT has been used for quite a while across the world. In other countries that engine is spec'd for 5w30 or with sever duty 0w40/5w40 and many nerds like us use 5w30 in that engine, though I don't think it's quite as hard on the oil like the FA24DIT has shown to be. While the FA24DIT is based on the same architecture, nobody has gone deep enough to see that all the clearances and other factors are the same. You could argue that bearing clearances can't really get any tighter than they currently are, there are other areas of the engine that theoretically could be affected.
To counter that though, the Ascent owners manual does state that "If 0W-20 synthetic oil is not available, 5W-30 conventional oil may be used if replenishment is needed but should be changed to 0W-20 synthetic oil at the next oil change". Also there is another note that state: "Engine oil viscosity (thickness) affects fuel economy. Oils of lower viscosity provide better fuel economy. However, in hot weather, oil of higher viscosity is required to properly lubricate the engine." So one would assume that an energy resource conserving 0w30 should be just fine. Also some in hot areas use 5w30 in the Outbacks and Ascents with this engine.
It’s kinda hard to make any reasonable analysis of this report since the engine still seems to be shedding quite a bit of material and it needs to be FLUSHED OUT first, before you can determine if the 0w20 is too thin.
From what it sounds like, based on the typical driving conditions, it should be just fine but there’s nothing wrong with bumping up to a solid 5w30 or even thicker simply to have more leeway in viscosity to account for extra idling, fuel dilution, etc. I think it’s silly to allow for a sheared down 0w10 to “protect” your engine.
Besides, any el cheapo synthetic is rated for -30F pour point, so there’s really nothing to worry about and only benefits of extra thickness for more cushion.
Mobil’s 0w30 fuel saver (which is what I think you bought) starts out at the bottom of the 30 scale and will quickly thin out into the 20s so you’re basically right back where you started.
If you want to stay with 20s, you need a very strong and durable brand then, with approved certifications from Mercedes, BMW, Porsche, etc on the bottle.
That's why I posted this as I'm not very knowledgeable when it comes to deciphering UOA's. I know this engine is still "breaking in" but I haven't seen many UOA's where a 0w20 has sheared down to essentially a 16wt. I've seen FF 0w20 on cars with over 5-10k where the 100c Vis is still at 7.00 or higher. I agree that it's odd how Subaru expects 0w20 to last 6k/6mo (OM Recommendation) miles in any circumstances. I certainly wouldn't consider our use as "severe service" that would justify 3k mile OCI's, generally I stick to 5k OCI's which I'll be changing oil again around 15K which should be 4-6wks from now. It's gently driven most of the time, in the winter it is idled for extended periods for warm-up but I wouldn't consider it excessive as Subaru remote start only allows 2 10min intervals, long road trips are usually 80mph, sometimes 85mph on the interstate but in IA, SD and NE it's small rolling hills with no large elevation changes and our city isn't large enough to consider long periods of stop and go IMO.
I agree that stepping up to a good 5w30 should be no issue either. I just prefer a 0wXX for piece of mind in our climate. I do recall that Pennzoil Platinum is a pretty tough oil and tends to be on the thinner side of a 5w30, so it would be a good choice in my eyes if the 0w30 M1 AFE doesn't pan out.
The thing about M1 0w30 AFE is that there is only 1 or 2 VOA's on it that I have seen and I haven't found a single UOA. I've tried searching but didn't come up with anything. I prefer off the shelf oils vs boutique oils I have to order online. I like to support local businesses (though Walmart is hardly what I consider local), I like to just go get it when I need/want it and generally boutique oils are considerably more expensive. Outside of Schaeffers 0w20 (VI 174 and usually lots of Moly) and M1 EP 0w20 (VI 173), I don't know if there are many boutique oils that match or better that. M1 AFE 0w30 has a VI of 166, which isn't as good as the 0w20's but I doubt it will shear down to a 16wt in 5k. Only one way to find out though. The only reason I don't consider Schaeffers a boutique oil in my case is that I can get it locally for a reasonable price. I have looked into Idemistu 0w20 as well, but it's spec sheet doesn't indicate that it would perform any better. If you know of any other 0w20's with that may hold up better, I'm all ears depending on the price of course.
