1993 Chevrolet Lumina Owner's Manual - Page 265

Schedule I Is any of these truefor your vehicle? Most trips areless than 4 miles (6 km). Most trips areless than 10 miles (16 km) when outside temperatures are below freezing. The engine is at low speed mostof the time (as in door-todoor delivery, orin stop-and-go traffic). You operate your vehiclein dusty areas. You tow a trailer. (With some models, you shouldn't ever tow a trailer. See the Index under Towing a Trailer.) If any one (or more)of these is true for your driving, follow Schedule I. Schedule I1 Follow ScheduleI1 only if none of the above conditions is true.