This is going to be one hell of a test tonight! I'm driving a 100-ish mile segment this evening in my girlfriend's car ('04 XC70). Not only is this thing heavy and inefficient to begin with, but it's going to be loaded to the gills and driven through the pouring rain at highway speeds. I'm looking at it as an entertaining challenge but there is really no telling how this will go. EPA highway is 24mpg. Wish me luck because I'm going to need it!