It gets fairly cold in the winter here (east of Albany, NY). In fact, right now it's 2 degrees. I think gas is 10% ethanol year round here (except for high test, which is ethanol free). I'm wondering how much of a hit winter blend fuel has on fuel economy? I realize winter is not a good time for mpg's, regardless. The interwebs seem to indicate it is a factor. Thanks.
Hard to quantify just the fuel itself effect on winter driving in colder climes. As you’ve found from your interweb searches, lots of things working against us re: miles per gallon/liters per km (or km per liter) in the winter – the US winter blend fuel itself (higher Reid Vapor Pressure = more lighter fluid (butane) in it, overall lower density), higher air density with colder temps (more aerodynamic drag resistance), longer times getting engine temps up, more electrical loads from heated seats/defroster/etc. Somewhat surprising numbers on the outsized contribution of higher air density with colder ambient air temps to reduced fuel economy – it seems to be the biggest factor. And of course, highway driving vs. putting around town in sub-freezing temps, headwind vs. tailwind, etc. Fuel Economy in Cold Weather | Department of Energy Learn the facts: Cold weather effects on fuel efficiency Atmospheric Effects on Aerodynamic Drag Anecdotally @Hammersmith (N. Dakota) and @KMO (Finland) could probably share their observations on winter city vs. highway drives.
Different regions get different seasonal blends, so there isn't a single answer your question. Around here, all the usual octane ratings are E10. Customers wanting E0 must go to specialty outlets, such as marinas.
