Headwind

And going the other way will get you close to 60 mpg going 75 mph. Been there, done that.

 

Yes it does! On a return trip from Florida I drove 400 miles into a steady 25-35+ MPH wind and the temp went from upper 50's to the upper 20's--was snowing by the end of the trip!

Due to time and freeway conditions I drove between 72-80 MPH (w/ cruise) and my MPG was about 31.

On the plus side the car handled well in the wind even at high speeds and I made it on one tank of gas (barely).

 

Hi Mike,

So what was your ground speed? If it was 70 mph, then your air speed was 105 mph. As most drag is aerodynamic above 60 mph, then the 105 mph is close to the load the car is under at 105 mph road speed, and zero wind speed.

I am wondering what the fuel economy is of other cars at 105 mph? 15?

 

Unfortunately, every car out there reports miles travelled at the ground not miles of air travelled through. Weird, I know. If you calculate how many miles of air you went through per gallon you probably wouldn't be dissappointed. New project for those adding instruments is to add air speed and air odometer gauges.