Bingo! This is the reason I stick with roof racks. I take about a 10 to 12% hit on mpg in either of our cars which are small - but with a space case and bikes or snowboards/skis we can road-trip and still be in the 23 to 25 mpg range and can park anywhere in the city. A fairing makes a big difference also in terms of noise and to a lesser extent mpg.Funrover said:With a trunk rack you get better MPG's, but I feel A LOT better with the roof rack. It cuts down on the mpg's but I use it for more than just bikes.