2010 GMC Yukon Owner's Manual - Page 22

D (Drive) : This position is for normal driving. It provides the best fuel economy. If you need more power for passing, and you are: . Going less than about 35 mph (55 km/h), push the accelerator pedal about halfway down. Going about 35 mph (55 km/h) or more, push the accelerator all the way down. M (Manual Mode) : This position lets drivers select the range of gears appropriate for current driving conditions. If the vehicle has this feature, see "Range Selection Mode" later in this section. Notice: Spinning the tires or holding the vehicle in one place on a hill using only the accelerator pedal may damage the transmission. The repair will not be covered by the vehicle warranty. If you are stuck, do not spin the tires. When stopping on a hill, use the brakes to hold the vehicle in place. The vehicle has a shift stabilization feature that adjusts the transmission shifting to the current driving conditions to reduce rapid upshifts and downshifts. If the shift stabilization feature determines that a current vehicle speed cannot be maintained, the transmission does not upshift. In some cases, this may appear to be a delayed shift, however the transmission is operating normally. . D (Drive) or M (Manual Mode) can be used when towing a trailer, carrying a heavy load, driving on steep hills, or for off-road driving. You may want to shift the transmission to a lower gear selection if the transmission shifts too often. Downshifting the transmission in slippery road conditions could result in skidding. See "Skidding" under "Loss of Control" in the owner manual for more information. When temperatures are very cold, the transmission's gear shifting may be delayed, providing more stable shifts until the engine warms up. Shifts may be more noticeable with a cold transmission. This difference in shifting is normal. 3-8