Hello Everyone. I am Brand new to this forum. I wanted to post my sucess with Mobil 1 Synthetic. I have a 1987 Toyota 4x4 with 419,000 miles on the engine. I have run nothing but Mobil 1, and i have changed the oil and filter every 10,000 miles. I used an AC Delco filter every change. As of today, the engine does not leak, or burn a drop of oil, i simply change the oil, throw the cap on the bad boy and dont even worry about it. I just recently bought a 2003 Chevrolet Cavalier and i am repeating this process, only changing the oil every 7500 miles instead of 10,000. This allows me to go by the "long trip" instructions in my manual. Just wanted to say that Mobil 1 has done wonders for me so far, and I am going to continue to use it.