Leaddie,
I also wonder about the issue of higher tech auto oils, and the products like aeroshell 15W-50 is a better option as you suggest.
The biggest problem with say Mobil 1 which is the leading synthetic auto oil is the use of AVGAS and the deposits in the oil. Hence the semi synthetic blends like the Aeroshell and others.
Heating and priming the system has to be worth it with infrequent use engines.
J