Wind affect on MPG

Oh, I absolutely agree. Although I've never seen anything as low as 38mpg, the winds here in Vegas do have a definite impact. A month or so ago, I made a road trip to Laughlin, NV. On the way there, I got 58mpg. On the way back, I got 47. There were a lot of cross-winds.

My theory is that the more aerodynamic a car is (in a forward direction) the more susceptible it is to cross-winds. My old 1g Scion xB got poor mpg on the highway, but didn't get much worse when it was windy.

 

There have been some brutal wind in the Vegas area lately. I've had drives where it was a struggle cruising at normal highway speed due to a head wind, so I'd just look for a conga line of vehicles to draft behind.

Cross winds make for a tiring drive, too. Sometimes I make a mental note to get my alignment checked, not realizing the wind is blowing me to one direction.

 

I've seen 37 to 38 mpg when crossing the Cascade mountains with a headwind. The same occurs on the flat when I'm in the Columbia River Gorge. Wind takes a terrible toll on mpg.

 

Yup.

From my observations, agreed. My theory is the cross-wind disrupts the aerodynamic flow over the car.

I have had the opposite with tail winds in both directions. That makes for impressive MPGs.

 

I agree that cross winds seem to be even more of a drag than headwinds for the Prius. But headwinds are no treat. And, statistically, if you're going to have wind, 2/3 of the time it will be either head wind or cross wind, which really stinks.

On our trip to Ohio in Nov/Dec, we had 20_ mph head wind as well as rain going both ways, plus a fully loaded car. It was a real struggle to manage 50 mpg. Had I just set the cruise and let it go as usual, it would probably have been under 40 mpg.

Just once, I'd like to make a long drive with a tail wind.

 

You didn't mention speed.
That has a huge impact on fuel consumption.......because you are bucking a stronger "wind" the faster you go.
And it always is a headwind.

 

Yup. Nebraska and I-80. I used to go back & forth between Iowa and Colorado quite a bit. I remember one time on the motorcycle that was kinda scary. Leaning to the right at about a 45° angle as I went west and having to be super-careful as I passed semis to not get sucked under the wheels when they suddenly blocked the wind or blown off into the median when I finished the pass.

Worse yet is the chinook winds in Colorado. My wife and I actually got blown over one night on the bike. Thankfully, we had just stopped because it was so bad. Those are not consistent, but they are pretty frequent.

 

Well, not always. If you are doing 90 though, and still have a tailwind, you should either go faster, or find a good tornado/hurricane shelter

 

We hit some really nasty winds out your way a few years ago driving a Honda Oddessy. We were going west headed up into the mountains on I-8. Head winds were something like 80 mph according to the radio. Came around a bend to find a tractor-trailer rig laying on its side spanning all three lanes. The state patrol had just arrived and we managed to sneak by on the shoulder a few seconds before the closed the road. BTW, the Oddessy makes really weird noises driving at interstate speeds into an 80 mph wind.