Yall are funny.
So, is there something wrong with my Corsair GT or is this what I should expect for cold weather highway mileage? @greerl is correct. The Corsair weights 500+ lbs more than the Ford Fusion hybrid. I've had the FFH and the MKZh, plus as this is my second Corsair GT. Shockingly, the MKZ got less mileage with the same system. Why? its heavier. The same principles that apply to an ICE vehicle also apply. Forget the fact the original post said less than 10k miles. The engine still has to break in. Even the EV motor and battery breaking in time to get going. Last I checked, most manuals tell the driver/owner something like that for the first 2000-5000 miles of breaking it in. Second, just like the AC/heat hurt the ICE mileage, the same goes for the Corsair. Plus, I know at that temperature, you are running the heat, defroster, etc. That further kills mileage.
"This is an average of 23.98 mpg, just horrible in my opinion. I have filled up 9 times, I can barely get 200 miles before I feel the need to fill up since in these conditions, I don't let it get below 1/4 tank."
Plus, I challenge your math. Its an 11 gallon tank. that's 99 gallons. If you fill up at 1/4 left, it should be 75 gallons. I too keep gas logs. I've driven 700+ miles several times with one fill up after a full tank. Even in hybrid mode, I've gotten 38.4 and 36.3. The worst I ever got was during Christmas, which is why I know all of these things. That tank was 33.2, but all of these in the summer. The best tank I've ever done was 1761 miles. I plugged up CONSISTENTLY, but only got gas once in five weeks lol.
First problem of cold weather, if the temperature reads under 32, is that the vehicle will start the engine. NOTHING you can do about it. I believe its part of the programming to keep the ICE in great condition. In EV mode, if you run the car heat, seat heaters, and steering wheel heater, you will blow through EV miles too.
Finally, another poster said this too: do not worry about the individual trips. You haven't had the vehicle long enough to compare trips. The Corsair is programmed to learn to drive WITH your style to maximize mileage. There really is an increase when you drive in conserve mode. Why? It charges the battery enough to then go back into EV mode in shorter sprints. Did you check for chargers when you stopped? You can always pick up 10 EV miles in an hour, then use that to get more EV miles.
hope that helps.