Estimating the Winter Mileage Tax

when i was running my gen II's about 15 miles a day, the mfd would drop from around 65 mpg at best, to 55 mpg at worst. that was using every strategy i could think of do mitigate the issue.

 

I may not live in the Northern extremes of the USA; however, I do live in Indiana and we do get cold winters. I purchased my new 2015 Prius C last month, and I am on Fuelly. I commute 80 miles round trip each day, so I will be able to compare my last month's average to the winter months ahead. Same username on Fuelly as on here.

 

It's almost more of an east-west thing. I mean, we're in the "great white north", but seriously, our west coast winter isn't that different than Oregon, let alone Washington. I mean, comparing to someone in the north central States, we're in the banana belt.

 

I don't think that mpg estimate on the Prius car display is that accurate. I know for a fact I was getting much better gas mileage in the summer time (probably with summer blend gas), but my MPG display doesn't show much a discrepancy. Just when I'm filling up, I notice I put way more fuel in the car than I should.....and I don't get as many miles.

 

you get winte blend in la?

 

Yes we get a winter blend here in CA. In summer heavy driving season, they have to use a more expensive formula that reduces emissions.

 

Here in Las Vegas, my C will do better in the (cooler) weather as the A/C isn't as taxed. For the month of Oct I averaged around 55MPG.

 

Four winters with a Prius in Iowa and on average I take a 20% hit on fuel economy between summer and winter (summer around 50+ mpg, winter around 40+ mpg). Same difference on my non-hybrid vehicles.

 

Here's the mileage I've gotten for each fillup, living near Washington DC.

It starts in September 2014, and goes to October 2015
51.8779
51.94631
54.79042
52.73366
50.24079
50.57285
47.35103
46.78657
45.29866
46.38568
43.46834
40.02859
45.36011
46.39089
45.98467
46.1026
40.81025
39.57509
46.81859
49.05199
51.48891
53.00582
52.29531
52.69938
54.46077
50.08777
53.87205
51.05571
53.65739
51.76751
50.01238
52.92547
49.95934
52.4968
51.37663
52.90083
51.76607
54.50788
52.32216
51.83612
52.75862

As you can see, the warm weather gives me 50-54 mpg, and the cold weather gives me 40-47mpg. It's realistically more like 45-47 mpg in cold weather, and 40ish mpg in the snow/ice where I brake/accelerate more often. That's what I've found for my driving style, climate, and driving pattern (my mix of highway and local heavily favors highway, but the morning commute at 8:30am on the highway is normally around 15mph, whereas the evening commute at 7pm is around 65mph).

For people with different driving styles, climates, or driving patterns, different results should be expected.