Gas mileage and tail winds

Just got back last week from a 1300 mile road trip to the deserts of southern California and I got the best mileage with an average of 13 mpg for the whole trip. About 100 miles were truck only as we drove around to see the local sites. Typically I get 11-12 mpg as my overall average driving 60 mph. The big difference on this trip was the very light or no head wind as I headed south. I did not check the official NOAA wind speed on the way down, but the flags I saw along the road were hardly moving. One thing that did happen that I have never seen before while driving south on Highway 62 from Yucca Valley to Palm Springs was the strong wind blowing thru the area. On Highway 62 it was a side wind but once we turned onto Freeway 10 heading south we had a very strong tail wind. In that area they have the San Gorgonio Pass Wind Farm with over 4000 windmills, San Gorgonio Pass is one of the windiest places in southern California. The trailer felt like it was being pushed along the freeway. On my Honda Ridgeline there is a sliding bar graph display of instant mpg. As the wind was pushing us the display would slide to 30 mpg and every once in a while it would go as high 40 mpg. As we headed further south the tailwind dissipated and it returned to normal readings. On the return trip we stayed overnight in Bakersfield. The next morning before heading home I checked the NOAA wind speeds for different towns along Highway 99 for the drive north. The wind was coming from the south to south east at 2-4 mph in Bakersfield and increased to 5-8 mph by the time we got home. The total distance was 368 miles and I averaged 14.4 mpg. It is amazing how much the wind plays in the overall mpg my truck gets.

We were leaving Cape Hatteras this fall as hurricane Mathew was coming in and had a really good tail wind on the 4.5 hour trip from Rodanthe to Roanoke Rapids, we averaged 17.1 in our Dodge Caravan