so basically I have been trying to add into a car and circuit simulation wind speed and direction, now I was thinking that cos degrees would work fine, so "wind direction - driving direction = affective direction." This works for head wind -1 and back wind 1 as well as side winds, 0 (no affect) however I am really confused (I know that cos(45) is 0.707) but don't I want it to be 0.5? I'm just thinking simply here that a 45 degree head wind will have a 50% impact on speed? yes? no? please can someone tell me how I should be calculating the affective wind direction tanks If I am being a complete twonk feel free to tell me.