I know this sounds crazy but I have been keeping a close eye on running 91 octane BP gas (ethanol free) and 87 octane regular, or so it says anyway, "ethanol free" and I have notice a huge difference in fuel efficiency. I'm talking 7 to 10 miles per gallon. I'm getting fuel from the same gas station by a major interstate so I can be reasonably assured the gas is fresh in both cases. It was 88 degrees today and I got back from my usual back road ride with a fresh tank of premium 55-65 mph constant and got 53.7 MPG with the regular unleaded 87 octane 43.3 is the best I can do. It it just me or does the computer make better use of premium? I was happy to finally have a vehicle that ran on just plain old regular gas but now I'm not so sure.