[aerohead]

According to the S.A.E.Journals and Transactions,a 10% drag reduction will yield: 5% increased mpg at 55-miles per hour,and 6% increased mpg at 70-miles per hour.This weekend's testing has given me some data to suggest that a 10% drag reduction is good for 11% better mpg at 100-miles per hour.The results are sketchy,so lets not take that to the bank yet.The data for 55 and 70 is good and General Motors Aero Lab is comfortable using the relationships.( I believe they did the original research ).