Cold weather = bad gas mileage?

[Kevin 1G Drummer]

Is my car just a freak, or have other people expierenced this as well? I've noticed it with other cars I've owned, but it seems by far the worst with my dsm. When the weather was warmer (30* and above) I was seeing about 23-24 mpg. Once Thanksgiving hit and the temps plumeted, I noticed my gas mileage went down to 18-19 mpg. I haven't really been letting it sit and warm up much longer than I did before, so I doubt that's the cause. I also haven't really changed my driving habbits. If anything, I'm easier on the gas pedal now than I was when it was warmer.

[turbotalon1g]

i saw this last winter with my corolla and i am starting to see it again.

i think it is normal, and i am not surprised to hear that it is more severe with a turbo'd car.

Aaron

[JET]

Yes, that happens with any car. Usually drops a good 10%.

[Andrew7dg]

I noticed the change also

Think about what the computer reads and adjusts for.

Coolent temperature sensor.
When they go bad, car doesn't want to start. Why?

Thats because the computer adjust the fuel ratio when it is cold so it will start and stay running.

It could be that you are buring a lot of fuel before the engine is warmed up and that is giving you high gas consumption

I am guessing cold intake temps play a factor in this also.

[Kevin 1G Drummer]

Yes, that happens with any car. Usually drops a good 10%.
I'm guessing it's something with the density of the air? I've also noticed that just cruising, I'm at a lower level of vaccuum (closer to 0 on the boost gauge) I suppose that could also have an affect due to the higher fuel pressure?

[Matt D.]

I'm guessing it's something with the density of the air?
Correct. Cold air is more dense which requires more fuel to see the same air/fuel ratio as when the air is warm. I struggle to get 20mpg in town during the winter with the Evo where as I normally get 22-24.

[JET]

The air has some to do with it, the rest is the grease in the wheels, tranny fluid, everything gets thicker and causes more drag. The engines run a little rich when it is cold out to make a little more heat too. That is why you don't have to put cardboard in front of the radiators anymore, unlike the old days of carbs.

[TwoTalons]

the rest is the grease in the wheels, tranny fluid, everything gets thicker and causes more drag. The engines run a little rich when it is cold out to make a little more heat too. That is why you don't have to put cardboard in front of the radiators anymore, unlike the old days of carbs. Bingo!

[Matt D.]

the rest is the grease in the wheels, tranny fluid, everything gets thicker and causes more drag. The engines run a little rich when it is cold out to make a little more heat too.
I don't buy that. My car sure is stiff when I start driving, but loosens right up after a bit. Are you serious about running rich to make more heat? I've never heard of such a thing.

[Jaei Sun]

So rather than having a high flow K&N type filter replace with the stock cotton/ paper filter, less air flow = less gas used :D