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Author: UKBB Big funky green star, 20000 posts Old School Fool Add to my Favorite Fools Ignore this person (you won't see their posts anymore) Number: of 701  
Subject: AC/Defroster sinks mileage Date: 2/3/2005 7:40 AM
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There's a loophole in how most hybrid gasoline-electric vehicles work, and countless gallons of gasoline are draining out of it.


Running the front defroster increases their fuel consumption drastically, as I discovered while driving three of them during Detroit's typically cold winter. Setting the air-conditioning on maximum cool has the same effect, so the problem is not limited to northern regions.
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The hybrids fell as much as 40 percent below the EPA mileage figures for combined city and highway driving during my recent test, which covered a mix of Detroit-area roads.


"This is clearly a drawback," said Joe Phillippi, principal of AutoTrends Consulting, a New Jersey firm. "The vast majority of the country is affected."


http://www.freep.com/money/autoreviews/phelan3e_20050203.htm

UKBB
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Author: mschmit Big gold star, 5000 posts Old School Fool Add to my Favorite Fools Ignore this person (you won't see their posts anymore) Number: 235 of 701
Subject: Re: AC/Defroster sinks mileage Date: 2/3/2005 2:29 PM
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This article is very misleading.

First of all they say that mpg falls by as much as 40%, but do not compare it to how much a conventional car loses in the same test.

Second, almost any ad-hoc test such as this will get lower than the EPA test, since they aren't running the exact same simulated course for the highway and city tests. Maybe their test would show 20% lower than the EPA test which would make the portion attributable to the AC/defrost only 20%.

Finally, they don't say how long their test was. This is a big factor for hybrids since they generally need ~5 minutes to reach max efficiency. Running the AC/defrost increases this time slightly. While this is a real drawback (for people who mostly make only very short trips), there is not much that can be done about it. But it is silly to say that this is a "negative" since during the few minutes of warmup time they are getting about the same mpg as a conventional car. That's like saying I don't want a car that gets double the mpg of my car because it only get the same mpg for the first few minutes.

As hybrids get more and more popular there will probably be more and more attempts to nit pick at everything that is different.

Mike

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Author: UKBB Big funky green star, 20000 posts Old School Fool Add to my Favorite Fools Ignore this person (you won't see their posts anymore) Number: 236 of 701
Subject: Re: AC/Defroster sinks mileage Date: 2/3/2005 4:27 PM
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Also from the article

Another idiosyncrasy affected the Prius I drove. Not only did the engine shut down very infrequently, but it often stopped and started several times during a single stoplight. Under ideal circumstances, the engine shuts down when the car comes to a stop and doesn't start again until you depress the accelerator.

Any Prius owners out there experiencing this?

UKBB

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Author: GameMaker Big red star, 1000 posts Old School Fool Add to my Favorite Fools Ignore this person (you won't see their posts anymore) Number: 237 of 701
Subject: Re: AC/Defroster sinks mileage Date: 2/3/2005 4:49 PM
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Yes, unfortunately. It seems like the defroster requires that the gas engine run, so it does. Then the controller says "Ok, that's enough - shut off the gas engine", so it does. Then it says "Wait - we need more juice...fire it up," so it does.

Etc.

The end result is that the gas engine seems to sortof stutter and start, never quite turning off and never quite turning on.

I've just lived with it, and instead try to keep the defrost on for as short a time as possible. I've also found that if I put it on max defrost, it tends to keep the gas engine more firmly "On", so at least it doesn't cycle on/off.

I will say that I'm not just skeptical I straight-on don't believe that the Prius got 22.8 m.p.g.

Even with the defroster on, I'm getting 44. Yes, it's down from the 50+ I was seeing before the cold set in, but still better than any non-hybrid or partial-hybrid.

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Author: Carpian Big red star, 1000 posts Old School Fool Add to my Favorite Fools Ignore this person (you won't see their posts anymore) Number: 238 of 701
Subject: Re: AC/Defroster sinks mileage Date: 2/3/2005 10:04 PM
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I agree the article is misleading, certainly to my experience. Yes, cold weather and running the A/C or defroster do reduce the gas mileage, but to attach a 40% figure to that reduction is ridiculous. My experience is probably closer to 5-10%--granted I don't experience in southern California the harsher temperatures of some other areas. It depends on a number of factors, as mschmit mentioned, especially how long your trip is.

I have a 5-minute commute to work, including going up a sizable hill. On that trip, I do get around 30 mpg, which would be a 40+% reduction from the EPA rating. But on the whole, since I do many longer drives, after a full year I'd say I average around 46-47 mpg per tank (in a 2004 Prius).

I haven't experienced any of the starting and stopping of the gas motor while stopped at a stoplight, it's always been a smooth shutdown when I stop, and smooth startup when I go again.



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Author: mschmit Big gold star, 5000 posts Old School Fool Add to my Favorite Fools Ignore this person (you won't see their posts anymore) Number: 239 of 701
Subject: Re: AC/Defroster sinks mileage Date: 2/5/2005 2:07 AM
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Since the author of the article didn't really document very many miles in the cold weather...here is a web site from someone who lives in Minnesota and shows every gas fillup for 10's of thousands of miles...over many years. He got 42 mpg in January.

http://john1701a.com/

Mike

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Author: Carpian Big red star, 1000 posts Old School Fool Add to my Favorite Fools Ignore this person (you won't see their posts anymore) Number: 241 of 701
Subject: Re: AC/Defroster sinks mileage Date: 2/5/2005 9:23 PM
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Also my favorite Prius review--in the middle of winter, they drove it as far north into eastern Canada as you can go by paved road. The mileage did suffer--7.1 liters per 100 km, around 33 mpg--but was still economical and the car performed well.

http://www.canadiandriver.com/articles/ly/jamesbay.htm

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Author: UKBB Big funky green star, 20000 posts Old School Fool Add to my Favorite Fools Ignore this person (you won't see their posts anymore) Number: 258 of 701
Subject: Re: AC/Defroster sinks mileage Date: 2/17/2005 12:50 PM
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Phelan responds:

http://www.freep.com/money/autoreviews/phelan17e_20050217.htm

UKBB

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Author: StringCheeseMark Big funky green star, 20000 posts Old School Fool Add to my Favorite Fools Ignore this person (you won't see their posts anymore) Number: 259 of 701
Subject: Re: AC/Defroster sinks mileage Date: 2/19/2005 12:32 AM
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Phelan must drive like a fat pig moron to get that crappy milage in a prius.....20-28 mpg. He'd have to stomp on the gas at every green light, brake hard and blast the radio and the run theheater at his full (I'm comfortable damnit) level while charging his cell phone and deflate all four tires to get milage that bad.

He needs to test the gas milage in his H2 with the heater on and his driving habits. I think he's the problem not the car.


scm

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