Hi all, I picked up 3 quarts of Rotella T 5w40 at Walmart today (enough for 2 oil changes and a little make-up oil). Anyhoo, while I was there I saw M1 15w50 for $26. Not cheap, but only a few bucks more than Rotella's true cost. I've read on here that their 15w50 is a fantastic oil and can be used widely with confidence. I was wondering about using it in my 2008 Subaru Legacy GT during April-October (i.e. no lower than 40-45 degrees fahrenheit likely). My main concerns with this engine are: Premature turbo failures - I want an oil that can hold up in that turbo under less than ideal circumstances. Lean running #2 cylinder - The stock ECU mapping lets one cylinder run leaner than preferred, and I want an oil that can take the resulting heat. I'll be tuning this engine eventually (i.e. out of warranty probably), which will take care of the lean condition. But I'd prefer to maintain it to a T until I don't have to worry about voiding a warranty, and to prepare it for the later usage. Thoughts on using this oil in this app in PA?