Is it bad for my Toyota Prius if I fill it up with racing fuel?
To briefly summarize: using higher than “regular” 87 octane gasoline in your Prius will just cost you more at the pump, lower your fuel economy, and probably give your Prius a check engine light. I’d also worry about what octane boosters are used in the racing fuel, if that may cause any degradation of the fuel line/emission system. (For example, is it more than 10% ethanol, or does it contain MMT, both of which would act as an octane booster.) Is the racing fuel even legal for street use in your state (emissions laws)? From my US 2001 Prius’ Owner’s Manual, page 144-145: “OCTANE RATING Select unleaded gasoline with an Octane Rating of 87 (Research Octane Number 91) or higher.” Quality gasoline, gasoline with detergent additives, and low sulfur gasoline are all preferred. MMT (Methylcyclopentadienyl Manganese Tricarbonyl) additives is not recommended. “OXYGENATES IN GASOLINE Toyota allows the use of oxygenate blended gasoline where the oxygenate content is up to 10% ethanol or 15% MTBE
