ok so its been around zero degrees (give or take 30degrees) for the last couple weeks and i've been getting really s***y gas milage.
does anyone know a reason? does it have any thing to do with havin a cold air intake on?
http://www.cardomain.com/ride/2134801
its probably just the cold weather and how long do you let the car warm up before driving. I live in wisconsin and its about 5 degrees and am getting about 19 mpg
well when i leave my house and i'm in a heated garage... and when i leave where ever i was at i usually don't let it warm up very long(couple minutes)
Colder air is denser, more tightly packed, more O2 gets in, so the computer throws more fuel in to keep the ratio at optimum. I.E., we are running rich, in a manner of speaking, ALL the time in cold weather. I notice my 'Fire runs like a bat outa hell right before fuel mapping goes from open, to a closed circuit.
Cold air being denser is also proportionally more heavier and therefore much more load for your car to push, especially at higher speeds.
The air pressure against your car multiplies as you go faster so the drag would be 4x the amount at 100 km/hr then 50 km/hr (rather than 2x the amount you have increased your speed by).
DartBaron wrote:Colder air is denser, more tightly packed, more O2 gets in, so the computer throws more fuel in to keep the ratio at optimum. I.E., we are running rich, in a manner of speaking, ALL the time in cold weather. I notice my 'Fire runs like a bat outa hell right before fuel mapping goes from open, to a closed circuit.
Dito. When I first start 'er up, wait a few minutes to let her warm up a bit, I swear the car drive 6 times faster until it warms up to almost running temp. I wish it did that at running temp. It'd be nice.
And also, when I don't give her time to warm up enough, I also get about 20-21 MPG.
thanks to all...
any other thoughts???
My '02 Sunfire normally gets about 30 mpg on the highway during the warm months. This figure drops drastically in the cold weather, probably due to the reasons already noted. I think that ethanol is playing a significant part in the declining fuel economy numbers, especially in the colder climates - but I am not sure. What I am sure of is that the energy density of ethanol is quite a bit less than gasoline, which means that you will not go as far on a gallon of ethanol as you will on a gallon of gasoline, no matter what the temperature of the air is. Here in New Jersey, motor fuels are approaching 15-20 percent ethanol by volume at the service stations I utilize.
Ethanol is a real political "hot potato". But that's another forum entirely! Drive safely.
WR
for cold weather, the sees colder intake temps, dumps more fuel, and tries to get the block warmed up so it dumps more fuel to try to get it up to operating temp. plus when you start your car, the oil is thick so it takes more rotating mass and force to move the oil and thin it out. plus like they say, the colder the air, the more gas or fuel it takes. im sure if my car was out then it would be even worse because of HPT.
