[JeepNmpg2]

Does a forward extending lip on an air dam do you any good? I'm working on a design that could go either way on this, but I am trying to weigh the benifits. I would like to keep most of the air from going under the vehicle, but I don't want to sacrifice any more aero that I have to. The dam is designed to be about half an inch lower than the lowest point behind it (front differential) and with a partial pan attached, should smooth the airflow that immediatly travels under the edge. After that, it's up to the skid plates to smooth out (with a few gap fillers where applicable) Bottom line is beyond the already flat nose of my vehicle, does a slightly extented lip do me good or harm?