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Ive had my prius since Aug 15th and got 40+ mpg . Now that the colder weather is setting in here in ILLinois. Im seeing a significant decrease.. Anyone got tips for cold weather driving to keep the milage figure up ??

Thanks Joe
 

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Johnigk said:
Ive had my prius since Aug 15th and got 40+ mpg . Now that the colder weather is setting in here in ILLinois. Im seeing a significant decrease.. Anyone got tips for cold weather driving to keep the milage figure up ??

Thanks Joe
Not many..you're gonna take a hit regardless.

1)As the temps drop so do your tire pressures. Keep them juiced up by checking them cold and getting them up to pressure before you start driving.

2)Also, minimize your AC use...set it to something comfortable...I usually just leave mine off if the temps aren't too bad (actually on the lowest fan speed vent setting (AC off/Max cold))..if it is cold enough to warrent the heater I find that 65 degrees is usually fine b/c I tend to be wearing a coat anyway if it's that cold outside.

3)Synthetic 5W/30 could help cold weather performance...some even go so far as to use 0W/30...though I don't.

Remember also that it's not just the cold that affects the mileage....most places switch to a lower BTU gas formula so you're getting less power out of each gallon.

Hopefully others can add more, but that's all I can think of at the moment.
 

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How much does air density effect MPG?

Obviously colder air is more dense, so it would be harder to push through... but it will also expand more when in the engine?

Which wins?
 

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cold air has a higher moisture content in the winter in a lot of areas so that will hurt you.

also, the cold air is worse because more energy is needed to heat it to the proper temperature that is necessary for a good burn.

when your Prius senses combustion is too cold, then the anti polution devices kick in which in turn, lowers your mpg's also.

where i live (pac nw, mild winters) the energy loss in winter formula gas appears to be about 8%. that is gauging by the difference experienced in mpgs from this tank and what i got during the period where it was cool enough to drive without air conditioning. right now, its frequently warm enough so that no heat is necessary, only a little defrost.

when it gets colder, then im sure my mileage will take another hit when i start using the heat on a regular basis. but my mileage without air was 54.8 mpg, with air; 52.5, so i expect a similiar drop for the heater. right now i am averaging 49.8 mpg, so i feel that 46-47 will be on track for me.
 

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gas mileage decrease in Michigan/hwy/town mileage discrepanc

Hi all,

I also have had about a 10% drop in mileage in the last six weeks. My dealer said it was due to "winter gas". I'd never heard of this but from replies below I see it is a fact.

Is 10% drop in mileage (from 52 on hwy to 46 on hwy and in town 47/43) something others have experienced this time of year? I see below an 8% drop but wonder how much less to expect?!

Also, one thing that has puzzled me since we got our Prius this past June: Our hwy mileage is always significantly better than around town in contradiction to estimates. Is this typical?

Sippy in Michigan :?
 

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I'd expect an even larger drop, maybe as much as 20% total due to the combined issues of winter gas, the cold itself, increased use of AC and defrosters, slushy roads and lack of traction, etc.

Still, if you have good habits and relatively long trips that allow for full warm-up cycle you should be able to do a lot better than anyone else out there.
 

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according to an article i read on polution in the wintertime, depending on your area, you will see an 8-14% decline in the amount of energy per unit volume of gas.

realize that regular gas has components (gas is a mixture, not a compound) that will freeze at around 40-45º F. that is reachable in all but a few select areas of the country.

also because of polution and other local issues, there are 42 blends of summer gas and 28 blends of winter gas. although the article doesnt specify, i suspect that some of the colder areas of the country might have two winter formulas.
 
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