How To Deal with Winter Weather
Q:
The return of cold weather reminds me of something. I’ve always had a sense that I get considerably worse mpg in the winter than in summer. I can’t really imagine why that would be, but it seems to be the case. Am I just dreaming?
A:
You are not imagining this. 
Those of us who live in the cold climes do, indeed, get noticeably worse mileage during the winter months. According to fueleconomy.gov, comprehensive testing of fuel economy shows that during short trips, the gas mileage for a conventionally powered vehicle is about 12 percent lower when the temperature is 20 degrees than it is at 77 degrees. And mpg can decrease by up to 22 percent for very short trips of three or four miles.
Moreover, hybrids are even harder hit: their fuel economy can drop by as much as 34 percent in 20-degree weather.
There are many reasons for this dip. Among them: it takes longer for the engine to warm up to its most fuel-efficient temperature; all those comfort-easing accoutrements like seat heaters and defrosters use extra power; the vehicle is experiencing increased rolling resistance because tire pressure decreases in colder temperatures (as evidenced by the fact that you’ll sometimes see the “low tire pressure” light come on when your vehicle first begins rolling on really cold mornings); and, in another tire-related matter, if roads are ice- or snow-slicked, the grip isn’t as solid – another energy waster. Also many people make the mistake of starting the vehicle and letting it idle for several minutes to let it “warm up” (completely unnecessary and a waste of fuel – just drive slowly for about one minute).
Many other factors reduce your winter mpg, but you get the drift.
You can minimize, to some degree, the cold-weather fuel-economy hit by doing a few things, among them: being willing to wear gloves and hat for the few minutes of the journey rather than cranking up the heating system to full blast to make the cabin living-room warm; parking in a garage when at all possible (including using parking garages when shopping and attending events rather than open lots); combining those very-short-haul trips into one longer one that will let your vehicle maintain maximum efficiency.
What's your car question? Email Sharon Peters to get some answers at sharon@ctwfeatures.com