I have a 91 Subaru legacy, 4cylinder, with 147K on the clock. I use 5w-30 in the car. As it sits now, it burns a little oil. HAve to add a 1/2 quart about every 500 miles. I was wondering if I should maybe run something a bit heavier, or lighter. I really dont know to much about oil, I did search, and I have talked to people about this, but figured I'd ask on here. Thanks.