While synthetic seems to be the new thing and it is advertise as the cat's meow of lube, the fact still remains that covential oil still gets the job done. I once met a man at the local flea market who was reselling stuff from the $1 store. He said if you mark this cheap stuff up to $5, people will buy it. I guess my point is, just because an oil costs more doesn't mean it is any better than regular convential in the life of a car. Many cars and trucks have gone well over 200,000 miles with covential oil. Rotella has been used in many diesels with over 1,000,000 miles. I guess my point is which ever choice you make the vehicle will fall apart before most engines will. There is just not enough benefit in $12 a quart motor oil to make most people use it. Amsoil is what it is...I won't use it, not because it's sold like Amway, but because it and along with most synthetics are just too dang expensive. Many that use synthetics claim that they don't have to change their oil as often. I ask them what about the filter? I would not leave any filter on a vehicle for the 25,000 interval Amsoil claims. If you change the filter, you might as well change the oil, so convential it is. Honda claims oil change intervals at 10,000 miles with convential Exxon Superflo/Honda oil. Most conventials will go 10,000 miles.