There is white smoke coming out of the tailpipe, and the car is sluggish when switching gears.
The combustion process gives off a small amount of water, so the white smoke could be from condensation in hot exhaust gases, particularly in cold weather.
In extreme cases, a head gasket rupture causes coolant to leak into the engine (often accompanied by a "sweet" smell) causing thick clouds of white smoke to spew. Coolant in the engine inhibits some performance, which may explain the lack of power.
I would suggest hiring a trained technician, like the ones at YourMechanic, to run a diagnostic to determine the source and cause of the white exhaust smoke, and recommend any necessary repairs.
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