Gas mileage......the weather(hmmmm.........)

has anyone noticed that the warmer the weather the better the MPG's.
over the winter i was averaging 180miles per tank. now that the weather is nicer (50-70 degrees) i'm getting 240-250 a tank.

the weird part is, this has only happend on my Chrysler vehicles.
had a 93 daytona (2.5) and lebaron (3.0) and the warmer the better.
seems like around 60-65 is best. i know motors run better on cool dense air. but this kind of a difference is just painful.

X Factor said:

has anyone noticed that the warmer the weather the better the MPG's.
over the winter i was averaging 180miles per tank. now that the weather is nicer (50-70 degrees) i'm getting 240-250 a tank.

the weird part is, this has only happend on my Chrysler vehicles.
had a 93 daytona (2.5) and lebaron (3.0) and the warmer the better.
seems like around 60-65 is best. i know motors run better on cool dense air. but this kind of a difference is just painful.

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I think they change the mixture at the gas pump for winter. Generally, if you use the same gas in winter as in summer you should get better mileage in winter. Cooler air brings better combustion, sometimes.

ditto, 10% ethanol in the winter around here. Not that i've seen my mileage jump like that though, seems a little strange to me. I could say, it does take your vehicle longer to warm up in the winter, including your O2 sensor, which, until it's up to temp, gives it all she's got, warmer weather, the O2 sensor kicks in faster, and actually regulates your air/fuel mixture.

Hmmmmm. just a thought.

Noticed a HUGE change in mine. Over the winter I was getting about 9mpg (150 to a tank), now that things have warmed up, i'm getting 15MPG (240ish to a tank. I know an engine is going to work harder in the winter and all but sheesh!

post states add something to the gas be it ethanol or what knows that they have cooked up lol. during winter you get less mpg then summer cause they know we let our cars warm up idleing long time and there trying to limit the emissions from the cars

99XJSPORT06 said:

Noticed a HUGE change in mine. Over the winter I was getting about 9mpg (150 to a tank), now that things have warmed up, i'm getting 15MPG (240ish to a tank. I know an engine is going to work harder in the winter and all but sheesh!

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No dude the engine will work harder in the summer, because the warm un-dense air and higher temperatures cause it to. In the winter the temps are cooler and when you have your heater running, the heater will suck some of the heat away from the engine. Not only that if you live in an area that gets snow, the slower speeds and being easier on the gas will help your gas mileage. Not sure of your discrepency though.

I've been getting worse mileage since its warming up. I get about 300 miles per tank in mixed driving (mainly hwy) in the wintertime and about 250 per tank (same driving) in the summer. Its been like that since it was new. Its because I have to use the A/C alot since its so hot here and my A/C robs a lot of efficiency from the engine. Also, I dont think they change the blend of gas here in the winter. Also, unless its really cold I dont let my Jeep warm up for more than a minute or so before driving it, I just take it easy on it till it warms up.

Actually it is the result of your winter air in your tires expanding faster and running at a higher pressure... when I increased my AT/KO's from ~30 to 40lbs I picked up 2mpg average...

skierbri10 said:

No dude the engine will work harder in the summer, because the warm un-dense air and higher temperatures cause it to. In the winter the temps are cooler and when you have your heater running, the heater will suck some of the heat away from the engine. Not only that if you live in an area that gets snow, the slower speeds and being easier on the gas will help your gas mileage. Not sure of your discrepency though.

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Well thats interesting. One would think that the colder the air is, the harder and longer it takes the engine to reach proper running temperature, therefore using more gas. That's how it seems to be working on both jeeps.