Right now I'm using Mobil 1 and a ST filter. The car is a 97 Grand AM (2.4 DOHC) with 83,400 miles. I usually change every 4-6 months because I drive less than 5K a year. Mobil 1 is good, but I think it's overkill for my situation. My trip to work is ~1 mile round trip, I occasionally drive around town for 15-30 minutes (less than 10 miles). Very rarely does it see long trips unless I have to go to a meeting. I'm considering the following oils, any tips or experiences with these oils are welcome. - Pennzoil HM - Pennzoil Synthetic - Mobil Drive Clean Plus (syn blend). - Rotella Syn. I know I want to go with something that is at least a blend. I just can't justify a $4+ per quart oil anymore. I plan to keep using the ST filter as I've been happy with it, and there is little else available in a small town. My oil & filter selection pretty much consists of what Wal-Mart has.