1998 Mercury Grand Marquis Owner Guide 1st Printing - Page 130

Maintenance and care Fuel quality If you are experiencing starting, rough idle or hesitation driveability problems during a cold start, try a different brand of "Regular" unleaded gasoline. "Premium" unleaded gasoline is not recommended (particularly in the United States) because it may cause these problems to become more pronounced. If the problems persist, see your dealer or a qualified service technician. 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 fuels 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. 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. Running out of fuel Avoid running out fuel because this situation may have an adverse affect on powertrain components. If you have run out of fuel: You may need to crank the engine several times before the system starts to pump fuel from the tank to the engine. If you run out of fuel, your Check Engine light may come on. For more information on the Check Engine light, refer to the Instrumentation chapter. Calculating fuel economy To accurately calculate your vehicle's fuel economy: 1. Fill the tank completely and record the initial odometer reading. 2. Each time you fill the tank, record the amount of fuel added (in liters or gallons). 3. After at least three to five fuel tank fill-ups, fill the fuel tank and record the current mileage reading. 130