Vehicle is a 2005 Subaru Outback LL Bean bought to replace my totaled 2007 Legacy. The Outback has the 3.0 Liter H6, 5 speed auto, and VTD awd. It's done 85xxx miles and will be my daily driver/personal adventure vehicle hopefully for a long time to come. The owner's manual calls for ILSAC GF-3 or API classification SL Energy Conserving or SJ Energy Conserving if SL is unavailable. The manual says 5W-30 is prefered for most temperatures with 10W-30 or 10W-40 for higher temperatures. For desert climates or heavy duty applications the manual calls for 10W-50, 20W-40, or 20W-50. I live in Northeast TN. Temps are usually 20's - 30's in the winter and 80's in the summer, though they can dip into the teens or reach into the 100's. Its primary use will be my Monday - Friday commute, which is ~ 40 miles round trip. About 2 of those miles are city and the rest are on the interstate at about 70 mph. On the weekends it will get me to the trail head with the dog and packs, bikes etc, or skis/snowboards in the winter. So maybe some fire road, or dirt/gravel trail light off road type use. I've taken a bit of a hit in fuel economy coming from my 4 cylinder/5mt Legacy so I'm going to try to drive the Outback as gently as I can and eke out as many mpg's as possible. Although I'm sure that I'll occasionally be unable to resist taking advantage of the greater power from the H6. The vehicle has no problems that I know of and hopefully it'll stay that way for a while. I used Mobil 1 5W-30 in the Legacy and would probably just continue with that in the Outback but figured I'd check into other possibilities first. Would I benefit from the 10W-40 or 10W-50? I'd love to be able to rack up the miles on this car for a long time to come and see how long it will last. 200K, 300K, or more? I wouldn't care to spring for something super fancy that I order online if that would help. I generally change the oil every 3-5K with a K&N filter. I don't know if those are considered a quality filter but when doing the change myself the 1" nut really comes in handy. Thanks for the help and any suggestions.