2005 Toyota Prius Owners Manual - Page 214

Break −in period Drive gently and avoid high speeds. Your vehicle does not need an elaborate break −in. But following a few simple tips for the first 1000 km (600 miles) can add to the future economy and long life of your vehicle: Fuel FUEL TYPE Your vehicle must use only unleaded gasoline. To help prevent gas station mixups, your Toyota has a smaller fuel tank opening. The special nozzle on pumps with unleaded fuel will fit it, but the larger standard nozzle on pumps with leaded gas will not. At a minimum, the gasoline you use should meet the specifications of ASTM D4814 in the U.S.A. and CGSB 3.5−M93 in Canada. Use of unleaded fuel with an octane number or rating lower than stated above will cause persistent heavy knocking. If severe, this will lead to engine damage. If your engine knocks...If you detect heavy knocking even when using the recommended fuel, or if you hear steady knocking while holding a steady speed on level roads, consult your Toyota dealer. However, occasionally, you may notice light knocking for a short time while accelerating or driving up hills. This is normal and there is no need for concern. GASOLINE ADDITIVES CONTAINING DETERGENT D Avoid full−throttle acceleration when starting and driving. D Avoid racing the hybrid engine. D Try to avoid hard stops during the first 300 km (200 miles). NOTICE Do not use leaded gasoline. Use of leaded gasoline will cause the three− way catalytic converter to lose its effectiveness and the emission control system to function improperly. Also, this can increase maintenance costs. OCTANE RATING Select unleaded gasoline with an Octane Rating of 87 (Research Octane Number 91) or higher. Toyota recommends the use of gasoline that contains detergent additives to avoid build−up of engine deposits. However, all gasoline sold in the U.S. contains detergent additives to keep clean and/or clean intake systems. 204