This. We've got a member or two over in the C-Max community who like to post crazy numbers like this but they do a lot of futzing with switching modes multiple times during a trip. It's not hard to get the 'guess-o-meter' up this high (inaccurately of course) if you really wanted to. Ultimately you are never going to get near those numbers unless you drove like 15mph with no stops or something equally ridiculous.
1. They were 175.00 at the dealer. The tech there told me I should have them installed by a profesional.
2. It took me 1 hr to install. Instructions were very good.
3. The hardest part was removing the center overhead panel very careful as not to break any of the plastic tabs for the cover panel.(just like the instructions tell you) It looks Ford mechanics had some trouble, because the very aft upper mesh piece was superglued together( don't try to take this piece off). Soldering the wires in a tight space was challenging as well but all in all it was kinda fun.
Any do it yourselfer will not have a problem.
I threw the instructions away or I would have taken a picture of them.