1993 Buick Skylark Owner's Manual - Page 270

Selecting the Right Schedule 0 First you'll need to decide which of the two schedules is 0 You operate your vehicle in dusty areas. right your for vehicle. Here's to howdecide which schedule to follow: 0 You tow a trailer. (With some models, you shouldn't ever tow a trailer. "Towing a Trailer" in See the Schedule I Index.) Is any one of these true for your vehicle? If any one (or more) these is true for your driving, of 0 Most trips are less than 4 miles (6 km). follow Schedule I. Most trips are less than 10 miles (16 km) when outside temperaturesare below freezing. The engine is at low speed most the time (as in of door-to-door delivery, or in stop-and-go traffic). Schedule I1 Follow ScheduleI1 only if none of the above conditions is true. 269