Chevrolet 2010 HHR Owner's Manual page 146

Up-Shift Light
When this light comes on, you can shift to the next
higher gear if weather, road, and traffic conditions let
you. For the best fuel economy, accelerate slowly and
shift when the light comes on.
While accelerating, it is normal for the light to go on and
off if you quickly change the position of the accelerator.
Ignore the light when downshifting.
If the vehicle has a
manual transmission,
there may be an up-shift
light. This light will show
you when to shift to the
next higher gear for the
best fuel economy.
No Lift Upshift (SS Models)
If the vehicle has the 2.0L turbo engine and manual
transmission, it has the capability of No-Lift Upshifts.
This feature maximizes vehicle acceleration by allowing
you to shift the transmission to a higher gear without
taking your foot off the accelerator. No Lift Upshifting is
enabled in all Electronic Stability Control modes. See
Electronic Stability Control (ESC) on page 5 6 for
more information. Use this feature only when the engine
has reached normal operating temperature. Correct
shifting allows the engine to maintain boost pressure
during shifts, while also keeping the engine from
over-revving.
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