Hmmmm the article in car and driver indicates that several different areas of the united states use a different blend of gas. And that currently as quoated from car and driver the Colonial pipeline company has 147 differnet fuels throught there network. Including Diesel and jet fuel. And also that the low sulfur emissions rules have been loosened up for political its almost time to vote reasons. Its really a good article i don't know if it is on the website or not Car and Driver but it was written by Patrick Bedard. Check it out is very interesting.