Chevrolet 2010 HHR Owner's Manual page 142

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 35 mph (55 km/h), push
the accelerator pedal about halfway down.
Going about 35 mph (55 km/h), push the
accelerator all the way down.
Downshifting the transmission in slippery road
conditions could result in skidding, see Skidding
under
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.
3-30
.
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.
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.
If the vehicle has this