Last august I made a trip to georgia. Before I left I fabbed up this airdam. It gave 5.5" of ground clearance. It was made from 26 gauge HVAC sheet metal. The first 3 hours of the trip netted excellent results(tailwind). Upon turning south mileage plummeted. I put 750miles on it with worse than usual mileage. I did some early morning 60-30mph coast down test. The results were very close but the without the airdam I got a very light improvement. This confirmed my suspicions that it was indeed hurting performance. The airdam certainly had its advantages, the A/C worked as good as stock at highway speeds. The added high pressure on the cars nose made for excellent cooling properties(Which was nice for a trip to Georgia in august). It also just looked cool. I couldn't have gotten more looks if I was driving a hot pink pantera. It was however impossible to live with. Even the most gently graded driveway would defeat it. Gravel is the enemy of any airdam. It wouldn't last 20 minutes on an icy winter day. The presence of mind required to prevent its destruction was mentally draining. I think for proper performance in my case the airdam and belly pan must be integrated together.
