May not be "scientific", but I can tell you without doubt that it takes a higher wattage (according to both PT G3 and Vector 2 meters) to maintain a given speed in a cross wind than in a no wind situation. I was curious enough to check this several times on the same piece of road, and the results were quite consistent. What's worse is the effect of a cross wind, unlike a straight head wind, cannot be noticeably mitigated by assuming a more aerodynamic position. Cliff notes version... I hate cross winds!