Every time you drive by a semi and feel your car get pushed away from the rig, it reinforces the reality that tractor trailers punch a big, ragged hole in the atmosphere. It takes a lot of power to force those big boxes through the wind, and Mercedes Benz is working to please both fleet operators and the environmentally conscious by taking some of these heavy haulers for a spin in the wind tunnel for a much-needed aerodynamic tuneup. Funk Flex