GMC 2005 Envoy Owner's Manual page 303

CAUTION:
{
Coasting downhill in NEUTRAL (N) or with the
ignition off is dangerous. Your brakes will have
to do all the work of slowing down. They could
get so hot that they would not work well. You
would then have poor braking or even none
going down a hill. You could crash. Always
have your engine running and your vehicle in
gear when you go downhill.
•
Know how to go uphill. You may want to shift down
to a lower gear. The lower gears help cool your
engine and transmission, and you can climb the
hill better.
•
Stay in your own lane when driving on two-lane
roads in hills or mountains. Do not swing wide
or cut across the center of the road. Drive at speeds
that let you stay in your own lane.
•
As you go over the top of a hill, be alert. There
could be something in your lane, like a stalled car or
an accident.
•
You may see highway signs on mountains that warn
of special problems. Examples are long grades,
passing or no-passing zones, a falling rocks area,
or winding roads. Be alert to these and take
appropriate action.
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