Hello all, I've been mixing Mobil1 10W-30 with a little (1 bottle or less) 15W-50 for my 2.0L turbo Subaru Impreza motor. Has anyone tried simply using Delvac 1 5W-40 in this motor, and if so are you pleased? My reason for mixing the 15W-50 in is the usual -- I want to keep use down a bit (my max use is now around half a quart per 4000 miles, driven hard and/or on long trips). I'm shooting for 5000 mile drain intervals. The D1 price from the site sponsor is attractive, so I'm looking for other people's experiences. Thanks!