1997 Ford Aerostar Owner's Manual - Page 234

Engine oil dipstick 6. Carefully pull the dipstick out again. If the oil level is below the "ADD 1 QT" line, add engine oil as necessary. If the oil level is beyond the letter "F" in Full, engine damage or high oil consumption may occur and some oil must be removed from the engine. Put the dipstick back in and make sure it is fully seated. 7. Adding engine oil It may be necessary to add some oil between oil changes. Make sure you use a CERTIFIED engine oil of the preferred viscosity. Your vehicle's warranty coverage may not apply if engine damage is caused by the use of improper engine oil. Add engine oil through the oil filler cap highlighted in yellow. To add oil, remove the filler cap and use a funnel to pour oil into the opening. Be careful not to overfill the engine. Recheck the oil level after you finish adding oil. Engine Oil and Filter Changes Change your engine oil and oil filter according to these mileage and time requirements, whichever occurs first. 235