Iâ€™ve become quite focused (addicted, some might say) to maximizing fuel efficiency. I have pulse and glide down pretty well: I easily manage 99.9 MPG segments if road and traffic conditions allow. My MFD shows 61.9 MPG for the current tank as of a while ago, and fillups have been well into the 50s throughout the summer. Now Iâ€™m working on maximizing high speed FE. Iâ€™ve read and re-read Hobbitâ€™s article about a higher speed potential â€œsweet spotâ€ as determined by a vacuum gauge: http://techno-fandom.org/~hobbit/cars/sweet/ I say â€œre-readâ€ because, though I have geek tendencies, I donâ€™t have a geekâ€™s technical or mechanical education. So if something like this is not written on a â€œsee Spot runâ€ level, it takes me a few tries. But the take home lesson seems to be simple enough: At higher speeds use â€œwarp stealthâ€ when conditions allow, and when they donâ€™t, in the Prius with no added instrumentation, keep the instantaneous MPG between 35 & 75. Iâ€™ve been doing both whenever possible. I now have more instrumentation available: I just bought a used ScanGauge I. (Thanks DarellDD!) Hobbit suggests using RPM as another indicator of the sweet spot, so Iâ€™ve set the ScanGauge to display that. The question to those familiar with his article (Hobbit, are you listening?): Assuming his theory to hold true, which of the other parameters available from the ScanGauge would be best to monitor in order to achieve and maintain this sweet spot, and what numbers should I aim for? Frankly, this mechanically uneducated brain doesnâ€™t understand what some of these things are. For those not familiar with the ScanGauge, I tried to attach a PDF excerpt from the manual that lists what it can display, but the attachment didn't take. Not sure if its because of this week's crash or a normal setting. I can list its various functions in the body of a follow-up message if needed. For those with a ScanGauge and who are not familiar with the article: Which ScanGauge parameters do you monitor, and where do you try to maintain them to maximize FE at higher speeds? Thanks in advance!