RAM 1500 Owner's Manual page 506

504 STARTING AND OPERATING
DRIVE (D)
This range should be used for most city and highway
driving. It provides the smoothest upshifts and down-
shifts, and the best fuel economy. The transmission
automatically upshifts through underdrive first and sec-
ond gears, direct third gear and overdrive fourth and
fifth gears. The DRIVE position provides optimum driv-
ing characteristics under all normal operating conditions.
To access all six available gears, you must use the
Electronic Range Select (ERS) shift control, described
below.
When frequent transmission shifting occurs (such as
when operating the vehicle under heavy loading condi-
tions, in hilly terrain, traveling into strong head winds, or
while towing a heavy trailer), use the Electronic Range
Select (ERS) shift control (refer to "Electronic Range
Select (ERS) Operation" in this section for further infor-
mation) to select a lower gear range. Under these condi-
tions, using a lower gear range will improve performance
and extend transmission life by reducing excessive shift-
ing and heat buildup.
If the transmission temperature exceeds normal operat-
ing limits, the powertrain controller will modify the
transmission shift schedule and expand the range of
torque converter clutch engagement. This is done to
prevent transmission damage due to overheating.
If the transmission becomes extremely hot or is in danger
of overheating, the "Transmission Temperature Warning
Light" may illuminate and the transmission may operate
differently until the transmission cools down.