2010 Toyota Tundra Regular Cab Owners Manual - Page 217

2-1. Driving procedures Column-shift type Upshifting Downshifting The initial shift range in S mode is automatically set to 5 or 4 (6-speed models) or 4 (5-speed models) according to vehicle speed. However, the initial shift range may be set to 3 or 2 (6-speed models) or 3 (5speed models) if the AI-SHIFT has operated while the shift lever was in the D position. (→P. 190)