I Have a Question

Yes in colder weather your car will have more power because colder air has more molecules which makes it more dense. The denser the air the more oxygen is in it. This creates a better combustion in the cylinders. The downside of this is that your car's computer senses this and increases the fuel to the cylinders. This makes you use a little more gas in the winter time vs Summer

Power and speed are different attributes, of course. So yes, denser air creates more power. Density Altitude seem to have far greater effect generating power than any drag/resistance they create. In drag racing, the sweet spot for times seems to be cooler day, but still warm enough for good traction to transfer power. Too cool and the traction suffers. Too hot and the power suffers. I've never seen anyone calculate differences in drag/resistance - at a track.