Recently I've installed MPGuino in Berta so I was able to see what and how much impacts FE. I was observing instant FE gauge during engine on coastdown. And I've noticed that 3rd gear of the blower is doubling fuel consumption over its 1st gear. Since I was driving in a very cold weather I was using blower for most of my trip. And I had to use 2&3 gears to get the windshield clear. Why? Because my cabin filter was dirty. I've replaced it with the new one and my windshield stays clear with 1st gear of the blower now. So remember to check your cabin filter regulary and if it's dirty just clean it or replace with the new one. It will save you some fuel, because you will use your blower less.
