In another forum, somebody just posted that they got way better mileage with a higher octane gas (in their case, from 86 to 88). They claimed that the overall savings, based on increase in MPG, was like $0.20 per gallon.

Of course I'm sceptical. So I was wondering if anybody here has had any experience with trying slightly higher octanes, and what the difference might have been, if any. Here in CA, I have heard that the 'winter blend' of gasoline gives poorer MPG, and so if the higher octane story is true, then it seems that this might make up for the mileage differential.