That kind of stuff will probably help me next winter.
In Canadian Maritime we have had like 2 full months below -20degres Celcius.
I wasn't able to have a better mileage than 6.5l/100km in town, when right now with an average temperatur oh 25degres C, I'm around 4.5 to 5 l/100km in town.
I will try the warm air intake next winter.