Join Date: Mar 2008
Location: Kapuskasing Ontario Canada
Mentioned: 6 Post(s)
There are several factors. ECU's fuel mapping may overcompensate by adding more fuel than needed to maintain desired air/fuel ratio in colder denser air in relation to intake air temperature sensor input. Higher oxygen content to air volume ratio yields more available power, but does not decrease engine's fuel efficiency.
Longer warmups and colder running engine. Oil temperature is lower and adds operating drag in engine and tranny from its higher viscosity. Wheel bearing grease is thicker when colder. Drive chain is a bit stiffer, etc... Wind drag is increased in colder denser air. Also, tire pressure decreases by about 1 psi per 10 degrees Farenheit drop. Be sure to adjust cold tire pressure in colder ambient air.
Last edited by invader; 03-24-2012 at 06:57 PM.