Civic tire spats ABA test (planning and results)
 

I have a second prototype set of front end tire spats on my Civic right now, and I am not convinced they are helping. Actually, I suspect they are hurting MPG, but I cannot be sure. I used online specs from a prius test for my design of the spats, but I have always planned to test them to see if they are a benefit to me. So in the next week or so I plan an ABA test. I have an 18 mile freeway course, but a good course for lower speeds is not likely--at least not more than 2-3 miles in length. Advice on what to look out for in designing the test?