Technically you have an average % of vertical distance covered on a selection of production vehicles, not an ideal size
Still awesome work though
It'd be great to be able to find an ideal size/shape/surface area, but that'll vary from vehicle to vehicle and driver to driver. (how much of a curb do you expect to climb over anyway?) The wheeldams on my car appear all but useless. Once my MPGuino gets assembled (one of these days dangit!) and I have some time I'd love to play with the airdams to see what, if any, benefit they have before I haul off and just fair the suckers.