Got back to work after the Christmas break and it was very windy here, I was working at a factory about a 100miles from home. I noticed that for the first couple of days I was getting about 46/47MPG, then the weather picked up and the wind dropped and on that day on the same route I saw the MPG pick up to 56MPG I am amazed that a windy day can make so much difference.
At higher speeds aerodynamic drag dominates in the losses department. Aerodynamic drag losses go up by the square of the speed through the air. If you make a 55 mph drive into 20 mph winds it is the same aerodynamically as driving at 75 mph. Turn around and it is the same as driving at 35 mph - not too hard to see why the big swing in mileage. Tom
Even a side wind will increase your drag significantly until it is from the rear quarter Crosswinds are almost always mor There used to be an interesting paper online where someone had taken loads of data on a GenII Prius and measured drag vs cross wind. If anyone knows where that is or has a copy, please share the link or copy. It may have been done by Wayne Brown who did the page I linked to above. That page appears to be part of an incompleted website, so it might be a good idea to save the actual page on your computer.
Yes front and side wind has a negative impact . I have experienced both and there are several other factors that impact mpg it can get complex.
I've had my cowl-less motorcycle's engine cut out when I was expecting to be able to drive another 30km with ease on the highway. Worked out my average had dropped from over 35mpg to about 22mpg since switching to reserve. Windspeeds of 50mph head-on caused this. I'm noticing the same with the Prius, but luckily the differences are not THAT big... I've had the same windspeed in my back on another motorcycle while doing about 50: surreal: a sudden total and complete absence of windnoise. Incredibly spooky. :jaw:
Hey, I was once bicycling with a 40+ mph tailwind. Now THAT was nice... ...until I had to turn right for the last mile of my trip. And then it started hailing. Ow. Ow. Ow.
