> From: Jed Rothwell >I used only premium > gasoline. I do not know whether this helps boost mileage significantly, but > I wanted to measure optimum performance.
The Prius engine was designed for 87 octane fuel. You could trigger an emissions sensor alert using premium (check engine light). The Prius engine uses the Atkinson cycle which actually benefits from faster burning, lower octane fuel. Nix the premium. You're damaging your ROI. http://www.hybridcars.com/discussion/discussthread.php?thread_id=81&replies=4 > seems the sensor does > not work well when the tank is full, This is likely because of the float mechanism. It probably pegs before the tank is full. It takes forever for my Echo to gauge to come off "Full". Speaking of ROI, payback between the Echo and Prius comes at about 68,000 miles (40 mpg vs. 50 mpg @ $17,000 delta) at $2.50 per gallon. Of course, the Prius is nicer!
