I wanted to put this out as it has been a subject discussed in several threads. We have had winter weather here in Alabama, ok cool to you Canooks ;D Along with others I have noticed a drop in general efficiency in the engine with the cooler weather. We went to 64 degrees a day or two ago and the truck ran great with a noticable increase in pulling power. It cooled down again and went back the the norm for cooler weather. It pulled hills about 5 mph faster than the day before and this was on the same fuel.<br><br>I am not trying to make a statement that the fuel is not effected by mixing in the winter, just that it involves the temperature also. Today at 22 degrees it took more fuel for the same runs as two days ago. Hey, this is Alabama at 9 degrees right now. :'(

 

I heard that Redstone was pretty much shut down yesterday due to a dusting of snow.<br>The colder the air is, the more dense it is (relate to weighing more). The optimum fuel to air ratio is 1:14.7 (1 lb of fuel to 14.7 lbs of air). For example (just show and tell figures, not actual); if the air at 100 degrees weighs 14.7 lbs, and at 0 degrees it weighs 16 lbs, you will use ~ 9% more fuel to go the same distance. Another thing that makes the fuel consumption even worse in cold weather, is that it takes quite a bit of energy to heat that air the extra 100 degrees, futher increasing the amount of fuel used. Overall decrease in miles per gallon will be in the neighborhood of 15-20%. The cooler the air, the more power due to the increased fuel flow.<br>Winter time I'll average 17.5 mpg and summer it will run around 20.5-21.<br>That took a lot out of me this early in the morning. Gonna go grab a cup of joe and take a nap.<br><br>shortround out

 

CH, The cold weather is kicking our a$$ here in Georgia, too. With the cold air, a lot off efficiency is lost in fuel ignition. The fuel is burning slower and more heat is wasted in just trying to get the fuel to burn rather than a nice quick burn giving you power. Timing is altered as the fuel burns slower and so you don't get the mileage or power you normally get on warmer days.

 

I always thought that since cold air is denser, it has more oxygen. The engine senses this and advances the timing and adds more fuel in. More fuel=worse mileage.