Although most folks here will sniff at 41 mpg, it is well above my long term average. Maybe if I could better control my plutonium right foot ... and maybe try a few of your supplements too, I might break the 40 barrier more frequently.
I always have used top tier fuel with the included additives they brag about. So, I'm not too sure how much I'd benefit. Cooler weather makes a huge impact on my short term average ... helps with the home power bill too, to the tune of about $100/month. Bring it ON!