rigormortis

Has anyone tried folding the back seats down in cold weather to help keep the batteries warm? I did it today during a 28º 40 mile drive (highway speeds) and was able to get 44 mph. Yesterday I was only able to get 38 mph with a 15 mph wind behind me at similar temps. Totally unscientific at this point and only based on one trip. ...thus my reason for asking if others have experimented :^)