can someone explain how cold weather kills MPG?

I just pull my polar bear out of the garage and ride it to work. Great mileage.

 

Does a baby seal cost less than a gallon of gas? Asking for a friend.

 

physics

 

In footballs, too.

 

If it is 20 degrees on Monday and you get 14.5mpg and 60 degrees on Wednesday and you get 17.5 and you didn't fuel up between then it isn't the gas. All of the fluids are thicker and more resistant to flowing at cooler temps (engine oil, differential oil, hub greese). Your tires flex a little bit with each rotation and that takes more energy when the rubber is cold. The engine runs richer for longer as it takes more time to warm up when cooler. Just because your coolant reaches operating temp, does not mean all of the other fluids are at their ideal viscosity. After 30+ minutes most of the fluids are completely warm and the mpg is usually about the same (less air density changes, possibly tire rolling resistance changes) as warmer (more ideal) temperatures.

 

Don't forget, if you are running with defrost on the a.c. compressor is running to reduce humidity. Also are you going by the dash mpg? Not always accurate.

 

Spinning an alternator by hand is not going to create the same resistance as the engine does. Doing it by hand does not create enough magnetic field to do squat.

Go buy an old school crank megger and test it on a good circuit, note the resistance you can feel.

Then go do the same thing on a short circuit (more draw) you can feel the difference in the energy required to crank.

The only thing that changed was the current draw. (Load)

You can also do the magnet down a copper pipe trick. Kids love it.

 

Very much agree with this. Absolutely true in cold places. All my point is, temps in the 60's, unchanged basically. Fill up with new gas and MPG goes from 19 to 17..........it is the gas.

 

Pretty much can do this with any hand generator set up.

 

Can we blame global warming?

 

You're spot on, colder air has more oxygen in it. Running in colder temps result in the O2 sensors sensing more oxygen thus using more fuel as the computer attempts to adjust the stoichiometric ratio. Warmer temperatures have less oxygen resulting in burning less fuel.

 

Moving the non aerodynamic truck through denser air also.

 

My biggest enemy is wind direction.