1. What kind of vehicle you have 2013 Subaru STI 2.5liter boxer 4cyl, IHI VF48 turbo at 17.5lbs peak boost 2. What your owner's manual says -- not just viscosity, but certifications (look for acronyms like API SM, ILSAC GF-4, etc.) and change intervals as well 5w30 synthetic, API SM or SN “ENERGY CONSERVING” or “RESOURCE CONSERVING”, or ILSAC GF-4 or GF-5. 3. Where you live San Angelo, Texas. Short cold winters with nights and mornings below freezing, and long HOT summers with daily highs over 110f. 4. How you drive (easy? hard? fast? slow?) Hard. I always hammer onramps, and in Texas you can't drive 5 minutes across town without using at least 3 onramps. 5. What your daily drive is like (short trips? long trips? city? highway?) Equal numbers and miles of: short trips across town (at least 10miles/10minutes in length) longer local trips (20-40 minutes) long road trips (3-5 hours between stops) 6. Whether your car has any known problems - New shortblock only has about 7k miles on it. 1st oil change from the Subaru factory fill was around 4k. - Aftermarket intake, downpipe, and ECU tuned with Cobb stage 2+ map. Price or OCI length is not an issue. I am looking to start track days soon, and want to keep the engine as protected as possible for the rigors of track use and harsh daily driving. Was thinking of Motul 300v?