Aeromods continue to deliver.
The manufacturer’s best highway mpg is 17mpg, which I could only rarely hit with tailwind in the past.
Return trip from Great Falls to Bozeman (271 miles / 11gal) saw 24.6mpg; this is 44.7% over the 17mpg best.
The trip out was a terrible headwind for 130 miles of 80mph; old mileage in similar headwind @ 80mph was 8.6mpg, this trip saw 13.8; a 60% increase.
The real number to consider is a comparison of the real actuals of mpg average improvement. Now 34 gallons for 685 miles @ 20.14mpg (Great Falls (plus 100 miles of xtra ranch trips) to SLC. Old was usually 45 gallons / 588 miles SLC to Great Falls @ 13 mpg.
The ratio of improvement from 13mpg to 20.14mpg is 55%. Two tanks of gas with an improvement of 55% proves out the third tank of gas no longer stopped for.