I was talking to a guy who owns, flanagan sauerkraut, the largest sauerkraut producer in the world. He was going on and on about how they used to go through engines in all their tractors, until they switch to synthetic oils. He said after switching to synthetics all the overheating problems they had went away. More importantly overall operating costs of running the tractors dropped significantly, from the engines lasting so much longer. This pretty much sold me on synthetics after talking to him. Just last year we started putting synthetic oils in our boat and it noticeably ran a little bit of a lower temp as according to the guage. So I do think synthetics are indeed a much better oil.
Same thing with the corvette, if you put anything other than mobile 1 into the engine it will actually void your warranty.
My mom's car, Saab (4cylinder Turbo), also runs Mobile 1. Believe it or not they recommend it to be changed every 10,000 miles and my dads corvette(8cylinder 5.7L) runs about 6000 miles till each oil change. So I am thinking the size of the motor MIGHT have direct relationship with service interval.
but the stuff works and if I can make my liberty motor last a little bit longer all the better.
Bennett