Chevrolet HHR 2011 Owner's Manual page 134

Notice: Shifting out of P (Park) or N (Neutral) with
the engine running at high speed may damage the
transmission. The repairs would not be covered by
the vehicle warranty. Be sure the engine is not
running at high speed when shifting the vehicle.
D (Drive): This position is for normal driving with the
automatic transmission. It provides the best fuel
economy. If you need more power for passing and
you are:
Going less than about 55 km/h (35 mph), push the
accelerator pedal about halfway down.
Going about 55 km/h (35 mph), push the
accelerator all the way down.
Downshifting the transmission in slippery road
conditions could result in skidding, see Skidding under
Loss of Control on page 5 14.
I (Intermediate): This position is also used for normal
driving. However, it reduces vehicle speed without using
the brakes for slight downgrades where the vehicle
would otherwise accelerate due to steepness of grade.
If constant upshifting or downshifting occurs while
driving up steep hills, this position can be used to
prevent repetitive types of shifts. You might choose
I (Intermediate) instead of D (Drive) when driving on
hilly, winding roads and when towing a trailer, so that
there is less shifting between gears.
3-28
PERFORMANCE SHIFTING: If the vehicle has this
feature, it can detect a change in driving patterns while
in the Intermediate position. If you make an aggressive
driving maneuver, the vehicle's transmission
automatically shifts to the lowest possible gear to
maximize vehicle performance. The vehicle will
automatically return to normal operation when you
return to normal driving patterns.
L (Low): This position reduces vehicle speed more than
I (Intermediate) without actually using the brakes. You
can use it on very steep hills, or in deep snow or mud.
If the shift lever is put in L (Low), the transmission will
not shift into L (Low) until the vehicle is going slowly
enough.
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.