I read most of the above test. First off, it was performed in 1994. A lot of change in oil technology has taken place in 15 years. It appears that the tests were performed to compare motorcycle and automotive oils to see if the extra $$'s for cycle oil was justified. In comparing petroleum motorcycle to automobile oils, there was virtually no difference in viscosity retention. The extra people paid for the motorcyle oil was a rip off. In comparing synthetic to petroleum, it showed the synthetic was better. In fact, Mobile 1 automobile oil appeared to be the best. Note, there was no mention of JASO ratings yet because it didn't appear on the seen until around 1999. (The JASO rating approved an oil for use in a wet clutch)
The new synthetic motorcycle oils meet the JASO requirement. Mobil 1 automotive 15W-50 doesn't neither does any other automotive oil, but by all means, use it if it's cheaper...no skin off my butt.
There is no right or wrong here. You can put chicken snot in your engine if it makes you happy.
Me ... I like Mobil 1 V Twin or Amsoil 20W50 Cycle oil.
