Why does my car run so much better when it's colder outside?

[walterturners]

I have noticed that my car runs so much better when its colder, under 40f outside. I know that this has something to do with a richer fuel mixture. How do I get this performance in the summertime? I drive a 2013 Ford Fusion and live in Texas where most of the year it's 80-100f outside.

[Inmaterry]

Hello. In general all is quite simple. Now, cold air is denser than warm air, so in cold weather the number oxygen molecules entering the combustion chamber per unit volume of air is significantly greater than when the temperature is high. More oxygen provides better combustion, and hence a noticeable increase in power.