Albert;
We like synthetic oil in our liquid-cooled motors.
They have an air filter change @ 250 hours. With a synthetic oil, we can go 200 hours on the oil change, versus 100 hours with regular oil. This allows for twice the hours between maintenance service if you change the air filter @ 200 hours.
I had a nice conversation with Bryan Ohaleck about the use of synthetic oil in his trucks. He was talking about using synthetic oil and only changing the filter and adding a quart at the normal interval.
I checked and there are automotive people who are never changing their oil after break-in.
Larry Cobb