I run Mobil 1 in an 03 Ford Ranger and Mobil 1 EP in an 03 Subaru Forester, because:
--You can run them 10,000 miles and thus don't have to change the oil so often;
--They lubricate better;
--They have been shown to keep the engine clean;
--I live where the winters are real cold and the syn oil does not thicken no matter how cold it gets, providing better starts that are easier on the engine;
--We plan to keep these vehicles for a long time and I want the best type of oil in them to help prolong engine life;
--I'm willing to pay a bit more for the best. I change the oil about once a year in the Forester and about once every 16 months in the Ranger (we're currently running 10,000 OCI's in each), so the extra cost over running a good dino out to, say, 5,000 mile OCI's is negligible.
I'm amazed at people who worry about such things as the price difference between PP and Mobil 1, the cost of Mobil 1 and Mobil 1 EP, the price difference between a good synthetic and a good dino, etc. I'm not going to worry about a lousy $10 or $20 per year per vehicle. That's the cost of about 3-7 gallons of gas, which we burn up every couple days in our two vehicles. That's the cost of a good dinner out. That's the cost of a case of beer. Get the picture? Its not worth worrying about, especially given the quality and advantages of a good synthetic oil. Besides, I can brag to all my friends that we run Mobil synthetic oil