Hello everyone. I run mobil 1 extended performance w/ mobil 1 extended performance filter in my 04 H63.0. Its our first winter in ND and I'm thinking down the road. I am confident with that combo both summer and winter in my car. My real concern however, is my GF's 92 legacy 2.2 with 220K. I have never ran full synthetic in it. Right now i have 10w-30 (for summer) valvoline maxlife. Which is a blend i guess. apparently this ole subby can leak a little oil out the valve covers. I am hesitant to put full syn in a vehicle that already leaks/uses a little oil, but want to give the car a break in -30F start ups? Stick with the Maxlife blend? I run a Puralator PureOne filter in hers. Thoughts? THANKS!!