I've driven my 2004 Prius nearly 50,000 miles and have tried almost all available brands of regular gas. Strangely, there seems to be a significant difference among brands even though my driving (over the 300-400 miles to a tank) doesn't vary much. With some brands MPG isn't much over 39 mpg for the tank, others get me 48-50 mpg. Interestingly, the best mpg comes from a little no-name local station...

Anyone else notice a consistent difference?