1998 Buick Century Owner's Manual - Page 100

AUTOMATIC OVERDRIVE (0): position is This for normal driving. If you need more power for passing, and you're: 9 THIRD (3): This position is also used for normal driving, but it offers more power and lower fuel economy than AUTOMATIC OVERDRIVE (0). Here are some times you might choose THIRD (3) instead of AUTOMATIC OVERDRIVE Going less than 35 rnph (55 km/h), push your accelerator pedal about halfway down. Going about 35 mph (55 k d h ) or more, push the accelerator pedal all the way down. You'll shift down to the next gear and have more power. (a): 9 0 9 When driving on hilly, winding roads. When towing a trailer, so there is less shifting between gears. When going down a steep hill. When driving in non-highway scenarios (i.e. city streets, etc.). NOTICE: If your vehicle seemsto start up rather slowly, or if it seems not to shift gears asgo faster, you something may be wrong with a transaxle system sensor. If you drive veryfar that way, your vehicle can be damaged.So, if this happens, have your vehicle serviced rightaway. Until then, you can use SECOND when you are driving less (2) than 35 mph (55 km/h) and AUTOMATIC OVERDRIVE for higher speeds. (a) 2-24