mpg will drop in cold weather
mpg will drop in cold weather on every car, hybrid and electric car will drop 30% due to weather and temp. Battery pack won't output max like in summer, also, car ecu unit will limit battery output in order to protect battery when it's cold. There is a orange cable from generator to the hybrid battery to warm up battery when car is running, but the heat is not enough. Toyota has to balance how warm they want battery to be, a little heat will not work, but too much heat will lead to overheat. If you really want to get summer mpg in winter driving, you have to remove back seat and floor, wrap or cover battery pack with heated blanket, there is aftermarket available, then wire blanket switch to the car, if you can do that, then you get max juice from battery in winter. Also winter gas blend affect mpg as well, but not as much as cold. You'll see mpg back up when temp back to 60 and above. I was on ford c max and prius before, rav4 is the same system as prius, just bigger and more hp output. On the gas tank problem, it's common, toyota is looking into it, it's a bad design on the tank and vaping system. Here is a trick, when you hear the 1st click and see gas pump stops, don't keep on pushing, If you pump more gas in and hear more click sound, it will cause damage to fuel and vaping lines in the long run. what you can do is, after pump stop 1st time, take pump out a little, to the edge of filling port, then continue to fill in, make sure no click sound. You can still fill up 4 gallon after 1st pump click. Shoot me a message next spring when warming up, see you can reach 38mpg again, it should be, then maybe by then, toyota will issue a tsb or recall to fix gas tank issue.