3990°F (2199°C)
Increased exhaust and combustion chamber temperatures. Low power due to lack of lower combustion pressure, excess air provides greater expansion ratio for combustion gases.
Colder temperatures have increased density and oxygen molecules. 10°F change above or below the standard 77°F (25°C) results in 1% power loss or gain. Extreme cold inlet temperatures can produce lower pre-ignition temps resulting in reduced fuel vaporization, longer ignition delay time and reduced power.
NOx gas formations and charge air cooling helps lowers combustion temps and NOx gas.
Combustion chamber is depleted of oxygen, more water vapour will dissolve versus cold days which decreases power and increases hydrocarbons, carbon monoxide and PM emissions. Older engines may smoke more on hot humid days.