Yeah--and there's also the undeniable cost of the additional gas burned just getting warmed up. I always view the rest of the drive (well to a large extent) as recovering from all the gas burned in the first minutes of my drive. When first thing I do is come to the end of my street, and if I can't make the turn because of traffic, I'm sitting there idling fast and wasting gas. And again at the next stop sign, and sometimes multiple cycles at the light that comes next. I can always--and sometimes do--turn the car off if it's still not ready to shut down the ICE at a stop, when I get to the light, but still, by that point odds are I've used a fair bit of gas regardless and there's no way of magically turning that into something other than 0 mpg for who knows how much fuel. And won't warm up enough to get to full-hybrid mode for significantly longer than during warm temps. My loss of FE dropped close to 10 mpg during the serious cold snap last winter. I really hope it'll be less severe this winter--like the lost gas while warming up just being a huge drag on your trip FE, low-FE tanks just drag down your lifetime FE. If not for those winter tanks, I'd be averaging around 40 mpg I'm sure, but instead I've been working to pull it up from maybe 35 after the winter. You burn through a lot more tanks at low FE than at high FE remember.