Syn oil has been around for a long time, being used by our military planes in WW 2, and the benefits of Syn oil can't be argued unless you want to weigh the benefit against price.
Along with the previous mentioned benefits Syn oil excels in lubricity because the molecules are all the same size where as in mineral based oils they differ in size.
As all ready mentioned, Would GM spend the extra money putting Syn oil in Corvettes coming off the line if there wasn't a beneficial reason for doing it.
I have been using Syn oil in my best cars since the 80's and have had excellent results, and I run it in two Kohler motors as well.
I don't run it in my tractors, not yet, because of price and because I have a huge stock of mineral based oil to use up.
The question of using it in an old Stovebolt motor has come up before and it is my opinion... There is not enough to gain to justify the cost. Greater tolerances in those motors,along with the fact that most are not a new motor makes the choice of a mineral oil adequate, provided you keep clean oil in the crankcase.
Dirty polluted oil is the main enemy to an engine.
I can find no reason not to use Syn oil if you can find the correct viscosity, and want to pay the extra for it.
Dan
