Colder weather has zapped my mileage to 44mpg

Among Japanese enthusiasts, we see 1% per 1C(1.8F) drop without using climate control.
So, we see 10% drop from 20C(68F) to 10C(50F).
If you turn on the heater, you'll see more impact.

Ken@Japan

 

Perfect, I concur. My MPG dropped 10 since I started my hwy trips and the temperature went down from 50F to 30F, i.e. 10C to around 0C... 10 degrees drop = 10 MPG, which is impressive 20% in my case.

I think no other car in the US (except other hybrids maybe) get a 20% MPG hit with 99% long HWY trips like the 2010 Prius... My lifetime MPG, once near 60 is coming down to 49 and will probably bottom down to 40 or less by the end of the winter... so, in reality, the Prius can't really keep up with EPA estimates in cold climates... I wish my salesman warned me about that Bummer!

 

Read the window-sticker.

Underneath that big 48 highway, it says: "Expected range for most drivers 40 to 56 MPG"

.

 

Cold weather makes good fuel economy a challenge for sure. But the story of how much of a hit winter causes is more complicated than just ambient temperature, because of associated variables like heater use, trip length, garage use, ice, snow, or rain on the pavement, and wind. These variables will vary by driver and location.

fwiw, I don't have any problems keeping mpg above 50 in my Albuquerque winter by taking a couple of preventive steps:

• I remove ice if it accumulates in the tyre wells
• Cabin heater is turned on when the ICE is warm, and turned off at stops in city driving.
• I definitely avoid short trips starting from a cold engine if at all possible.

 

We just got back from a trip to Longview / Kelso Washington, total about 140 miles.

Weather 30 degrees, dry roads, little or no noticable wind.

Round trip computer average read 50.2 MPG, by calculatons being miles driven divided by gallons used would be about 47 MPG.

During September the round trip would have had a reading of about 60 MPG -62 MPG on the trip computer.

Yes, it is obvious to me that winter or cold weather has more of an effect on, at least with our Prius, than any other car I have had. Like I said before my 2003 Jetta TDI Wagon Diesel 5-speed only takes a 2-3 MPG hit in winter and the aveage MPG is about 53 MPG for its 130,000 mile lifetime.

alfon

 

Exactly!!!

I'm not sure about other hybrids but the Prius high MPG is a misconception for those who live in areas where winters are harsh and long. A significant part of the US population lives in such areas. IMO that MPG caveat should be made clear by Toyota and dealers. A colleague, who owns a gen 2 Prius, warned me that the MPG drops significantly to a point where it compares to her Civic during winters but people in this forum and my dealer kept saying that Toyota addressed that problem in for gen 3. I think the small ICE and electric/gas cycling in the Prius precludes keeping ideal temperatures for FE. BTW, I'm finding the Prius to be a very FE car only when everything is perfect for it. Anything with minor adversity, such as short periods of light rain for instance, can easily deteriorate its MPG. I'm soon departing for another 360-mile long trip thru Northern IN, IL, and Southern WI. I'm going after the big snow storm coming up shortly, of course, but temperatures will be in the single digits and wind will be strong and blowing at temperatures 10-20F negative. This is going to be interesting. My CR-V in similar conditions in a similar trip last year, gave me a MPG hit of merely 5%... but I suspect I will break the 30% hit mark in my Prius in this next trip... To be safe, I will probably have to stop and fill up the tank in the middle of the trip, which is ridiculous for trip range of 360 miles…

Frustrating…

 

we are in the middle of a cold snap, but very different weather conditions.

first 3 days; temps high 20's/low 30's in morning. VERY heavy frost which meant a lot of defrost, scraping, etc. mileage (on MFD) 40-42 mpg on my 7 mile morning commute... all street speeds

last 2 days; temps in low 20's, off shore flow (humidity very low) means no defrost, but cranking the seat heater as soon as i get into the car. on this trip, i try not to run heat until water temp hits 125º. yesterday morning with temp at 22, max water temp only hit 152º and only very briefly. was hovering mainly at 145º and only for last two miles. but lack of defrost still saw my mileage in high 40's (48 and 46)

warmup at 35 mph was VERY slow. really seeing the value of that seat heater as it works very well and fast

 

That's only the case for short trips and does affect other hybrids, as well as traditional vehicles.

How would you quantify it, knowing owners like me experiencing harsh & long winters don't see as much of a hit?
.

 

oh!! and dont forget the caveat for people who live in extremely hot, humid climates who need to run AC all the time.

oh!! and lets not forget the people who live in mountainous areas who burn all that gas getting up the hill but can only regen ¼ of the way down the other side!!

oh!! oh!! oh!!

 

My quad cab pickup barely suffers a hit for any reason, weather, load, whatever. It's mpg uniformly stinks. Thus, I am thrilled with it. The EPA got it right. Mid-teens no matter what. Sure feeling smug that I don't own a Prius.

Sorry, couldn't resist.

 

A suggestion for drivers seeing large drops in MPG in the winter, and would like to avoid some of the hit:

Block the radiator
Use an EBH
Turn on cabin heat AFTER the ICE warms up

Honestly folks, this information has been available for close on to a decade now circulating among Prius drivers.

 

try telling that to your "coldblooded" SO when its 7 degrees out...wow its cold this morning!!

 

Short trips? My trips are 360-mile long and 99.9% hwy! Yet, my MPG hit is 20% right now in such trips and I'm afraid it will get to a 30% hit in bitter conditions...

 

I have a Prius Luna since nov. 9 and I noticed it too : higher consumption of one liter (from 4,6 L towards 5,9 L)

 

I noticed the 2010 Prius does not really start to blow warm air for a while from a cold start, probably waiting the ICE to warm-up, so it may be useless to wait...

Since you touched this, I must say that the Prius heater is terrible. Unless it is really freezing outside it makes a lot of noise and blows cold air instead of hot air, unless you set the interior tempreature really high...

 

short trips have bigger hit, but winter still will reduce your mileage and highway speeds reduce it more due to increased air resistance.

cold air is denser which means greater air friction that increases as vehicle speed increases

in cold weather, your car works harder to stay warm. defrost lowers your mpg's no matter how long the trip and we still have to deal with winter formula gas that simply does not have as much energy in it as summer formula gas.

another thing to consider; all cars suffer a loss in mileage. we only notice it more in the Prius because we get 24/7 up to the second feedback of how many miles we are NOT getting

 

I have found the heater to be very good. It blows warm air quickly, followed by hot air shortly after and it is very quiet. I keep it at 70-72 an am very happy with it so far. It sounds like you and I are driving very different cars.

 

I found the A/C in the new Prius to have little impact on FE and I did drive under hot and humid conditions during last summer. About the mountains, I suspect the MPG drop there in the Prius is disproportionably large too compared to non-hybrids, not sure.

Now, IMO, there are too many compromises in the new Prius at the expense of FE, and yet a very expensive car.

- Poor interior quality
- rattles/creaks
- Huge MPG drop during winter
- MPG drop at minimally adverse conditions.

Do I regret buying it? NOT AT ALL! This was totally financially justifiable. After all it is supposed to be a very reliable car as well, which matter a lot, big time! My commute changed from 10 miles a day to 100 miles a day and my Prius replaced a SUV. It is just that, based on my lifetime MPG before winter and considering a 5% MPG hit of any normal car during winter, I thought it would take only 1.5-2 years to my savings on gas break even, but now realizing the huge MPG drop during winters, it will probably take me 2-2.5 years instead... that's OK... I can live with that...

After I break even and actually “make some money†with my savings, my commute will also reduce in length (hopefully)… when that happens, I will be so ready to say bye bye to my Prius...