2000 Ford Focus Owner's Manual - Page 221

Maintenance and care The American Automobile Manufacturers Association (AAMA) issued a fuel specification to provide information on high quality fuels that optimize the performance of your vehicle. We recommend the use of gasolines that meet the AAMA specification if they are available. It should not be necessary to add any aftermarket products to your fuel tank if you continue to use a high quality fuel. They could cause damage to the fuel system that may not be covered by your warranty. Cleaner air Ford approves the use of gasolines to improve air quality, including reformulated gasolines that contain oxygenates up to 10% ethanol or 15% MTBE. Do not use gasolines containing methanol, which can damage critical fuel system components. Damage resulting from the use of methanol may not be covered by your warranty. 221