does cold weather affect gas mileage?

[Draigflag]

Could use a partial grill block so the engine warms up quicker?

[theholycow]

Originally Posted by Charon

Leaving the heater blower off until the engine warms does help the engine warm more quickly. In truly cold weather there is a hazard involved in leaving that motor off. If the defroster is turned on after the engine warms, the blast of hot air hitting the cold windshield has been known to crack the glass. Decades ago Americans stationed in Alaska were told to turn the defroster on as soon as they started the car, to avoid that very problem.

I cracked a windshield on a 1997 Pontiac kinda like that. I didn't wait until it was warmed up, I started it with the engine cold and fan on high then went back into the warm house until I could see that the ice on the windows was starting to melt. As soon as I touched it with the scraper it cracked.

[trollbait]

When cold enough that cracking the glass is a concern, I warm the cabin up by the dash vents first, or have the defroster on low fan and heat when the windshield is fogged up.

[tootal2]

Thanks, I will keep my fan on lowest speed till the car warms up

Originally Posted by Charon

Leaving the heater blower off until the engine warms does help the engine warm more quickly. In truly cold weather there is a hazard involved in leaving that motor off. If the defroster is turned on after the engine warms, the blast of hot air hitting the cold windshield has been known to crack the glass. Decades ago Americans stationed in Alaska were told to turn the defroster on as soon as they started the car, to avoid that very problem.

[bobc455]

Originally Posted by Jay2TheRescue

cold air is denser requiring more fuel

Not to be a nit-picker, but it's the other way 'round- the same amount of fuel requires less air. So density doesn't have an effect. (But yes, many other factors do affect gas mileage in cold weather!)

Don't forget that many states require "winter blend". Here in Massachusetts, starting on September 15th I can predict about a 5% drop in MPG, all in the name of "emissions".

[trollbait]

Originally Posted by bobc455

Not to be a nit-picker, but it's the other way 'round- the same amount of fuel requires less air. So density doesn't have an effect. (But yes, many other factors do affect gas mileage in cold weather!)

Don't forget that many states require "winter blend". Here in Massachusetts, starting on September 15th I can predict about a 5% drop in MPG, all in the name of "emissions".

I thought Jay was commenting on how cold, dense air takes more energy to push out of the way. In other words, increased drag.

[theholycow]

Originally Posted by bobc455

Not to be a nit-picker, but it's the other way 'round- the same amount of fuel requires less air. So density doesn't have an effect.

I'd say you're both wrong. Since modern cars mostly measure air by mass, it would be most accurate to say that it's the same mass of fuel and the same mass of air. (Granted, that air's volume is less.)