Bad fuel mileage in cold weather?

Yup, they burn less, and put out less power, eventually at sufficient elevation they will quit. Carberated engines used to have to be rejetted, sometimes three times between sea level and the summit, now days the fuel injected ones are re mapped automatically with input from the maf, map etc sensors.

 

Having a couple thousand pounds of snow and ice on the truck don’t help either.

 

Reading some of these comments, a airplane should never get off the ground!
The main reason your probably getting less fuel economy is because of cold tires, road conditions and extra drag from ice/ snow build up.

 

I don't know. However, when I was into drag racing cars, it was well-known that cars made less power and ran slower ET's and MPH at high elevation than at sea level, particularly forced induction engines. Most of them also required a different tune if they traveled to lower elevations to race.

 

YEA there is so much nonsense in post #21 I couldn't go threw it all.

 

This is absolutely normal. Many camping generators have label "XX Kilowatt at sea level" Less oxygen = less fuel in mixture = less power.
For winter fuel consumption most significant factors are
1. Fuel burning process slower due to colder air and fuel blend.
2 .Engine higher internal friction.
3. More power wasted to drive accessory - fuel pump, oil pump, PS pump.
4. Transmission, drive line, differentials.
5 Tire rolling resistance.
My truck has summer idle fuel consumption 0.4-0.5 GPH in winter 0.7 -0.8 GPH. Speed is zero.No dense air.

 

I get lousy mileage in my company truck during the winter. Also the truck slurps down DEF like crazy in subzero weather.

 

Can you explain that statement?
Seems like 2 separate things

 

I'm no engineer, however it seems to me that the engine is bringing in air and producing power even when idling...