Chevrolet Volt 2017 Owner's Manual page 183

182 Driving and Operating
Each time the vehicle is started, it
will return to Normal Mode.
Mountain Mode
Mountain Mode should be selected
at the beginning of a trip before
climbing steep, uphill grades and
when expecting to drive in very hilly
or mountainous terrain. This mode
maintains a reserve electrical
charge of the high voltage battery to
provide better grade climbing
performance. While driving in
Mountain Mode, the vehicle will
have less responsive acceleration.
Mountain Mode will not change
normal vehicle braking performance
for steep downhill grades. See Hill
and Mountain Roads 0 169 and
Electric Drive Unit 0 186.
Press MODE to select Mountain
Mode. If steep hill driving is
expected, it is recommended to
select Mountain Mode at least
20 minutes before driving on steep
grades. This will allow the vehicle
time to build a sufficient battery
charge reserve.
If Mountain Mode is not selected for
these conditions, propulsion power
may be reduced and the engine
speed may increase. See
Propulsion Power Messages 0 138.
The engine may run when Mountain
Mode is selected, depending on the
high voltage battery charge, to build
reserve battery charge for uphill
climbs. If Mountain Mode is entered
with a sufficient battery charge
reserve, the battery charge reserve
will appear grayed out and any
battery charge reserve still unused
upon exiting Mountain Mode will
return to normal appearance.
Press Mode again to return to
Normal Mode and it becomes active
after three seconds.
Each time the vehicle is started, it
will return to Normal Mode to
maintain a smaller battery charge
reserve for normal driving.
Hold Mode
Use Hold Mode on a trip where it is
expected that all of the electric
charge will be depleted. Use Hold
Mode mainly during highway or high
speed driving to maximize both EV
miles and fuel efficiency.