Good subject for discussion;
I’m in Minnesota and had the car all winter. First off, I do primarily city driving and have a short commute to and from work, 12-15 minutes on city streets. The warm up period is a killer on mileage, so I averaged about 34 mpg through early spring. In the first few tanks during warmer weather, I’m around 39-40 mpg. Some of the increase is a function of leaning how to drive more efficiently, but most is just faster warm up to normal operating temperature with warmer weather.

Re a block heater – I can’t imagine you could actually save energy by preheating the engine with electricity and very likely use significantly more. Electric energy is notoriously inefficient with huge losses in converting fossil fuel to electricity, more losses in transporting and more losses in the heating appliance, and even more in heat escaping from the block. Ultimately, you probably convert less than 15% of the heat/energy contained in the original fossil fuel into heat in the engine. On the other hand, using gasoline to heat your engine and move the THC at the same time is probably in the 80% plus efficiency range. Much of the lost energy in the ICE is given up as heat. Unless one is just chasing the highest mpg rating with no regard to the total energy used, a tank heater does not make much sense, nor does the remote start that Toyota forces us to buy in the north country.

Re instant heat… they are called heated seats, work great.