Found the straightest level piece of road that I could travel at speed to try and find the point on the speed/mpg chart that was equal. I held 49 mpg at 49 mph. It was on an 8.7 mile stretch of road. Temp was maybe 38 Fahrenheit at 1100 above sea level. Pics are of the new upper and lower grill blocks. I'll be testing them Monday over about 200 miles of highway.