Excellent point. Also true
Excellent point. Also true is that there is a minimum detergent level required by law. However, some fuel suppliers voluntarily meet a higher standard for fuel, but the Premium grade is not necessarily superior. I liked this story by Motortrend on the subject: http://blogs.motortrend.com/1403_all_fuels_are_not_created_equal_technologue.html
Thanks for expanding the topic. Cheers,