Best technique when driving in strong head/tailwinds

[Peakster]

Today, I was driving on the highway from Regina to Saskatoon and got a lovely 70+ mpg @ 50mph when the crazy wind was tailing me , but when I turned around heading back to the city, the same speed returned 34mpg .

So then I wondered:

If I wanted to average 50mph on the highway both ways, what would be the best driving technique in strong winds? Doing 50mph both ways? or say 40mph with tail wind and 60mph with headwind? Or vice-versa? Or would it make any overall mpg difference at all?

I'd test it myself, but the wind is always changing on the prairies. My gut feeling is that if my car is going to get crappy FE in the wind, I may as well cruise at a higher speed at get to my destination. Whereas if there's a nice tail wind, I'll slow down a couple mph and reap the great FE.

[zpiloto]

Originally Posted by Peakster

Today, I was driving on the highway from Regina to Saskatoon and got a lovely 70+ mpg @ 50mph when the crazy wind was tailing me , but when I turned around heading back to the city, the same speed returned 34mpg .

So then I wondered:

If I wanted to average 50mph on the highway both ways, what would be the best driving technique in strong winds? Doing 50mph both ways? or say 40mph with tail wind and 60mph with headwind? Or vice-versa? Or would it make any overall mpg difference at all?

I'd test it myself, but the wind is always changing on the prairies. My gut feeling is that if my car is going to get crappy FE in the wind, I may as well cruise at a higher speed at get to my destination. Whereas if there's a nice tail wind, I'll slow down a couple mph and reap the great FE.

The speed that gives you the best MPG that traffic will allow.

[ELF]

I hate driving into the wind but on my car the slower you go into the wind the better the mpg.
You should be able to cruise at higher speeds with the wind and still get good mpg. So I would vote for the 60/40 speed, at 60 you should get almost the same mpg with the wind as at 50. And at 40 your mpg should be a lot higher than 50 against the wind.

[omgwtfbyobbq]

Same as always, as slow as possible in top gear. Sometimes, I'll get lucky and can duck behind a semi into ~20-30mph winds, and take advantage of them on the way back, but it's rare.

[jwxr7]

I've been dealing with high winds lately too. This is how I've been dealing for my commute; If i am going to have a tail wind, I will take the highway like normal. If I'm going to encounter a strong head wind, I take rural roads. That way I can keep my speed lower and these rural roads tend to be more tree lined, and the trees are closer to the road. These conditions tend to help cut the wind forces on the front of my car .

[GasSavers_James]

Wind resistance increases exponentially with speed, so it would make sense to go faster with a tailwind (you will not be penalized by the higher speed as much), and slower with a headwind (yes as slow as possible in top gear).

[Silveredwings]

Originally Posted by James

Wind resistance increases exponentially with speed, so it would make sense to go faster with a tailwind (you will not be penalized by the higher speed as much), and slower with a headwind (yes as slow as possible in top gear).

If your tailwind is high enough, you can open the doors and drive "Wing-n-wing."

[Peakster]

Originally Posted by Silveredwings

If your tailwind is high enough, you can open the doors and drive "Wing-n-wing."

I actually thought about attaching a sail to my roof at one point today. It would be rather efficient on long highway trips and I could just raise and lower the sails on demand . Watch as the new 'hybrids' get this feature .

[rh77]

Man, I could've used a sail when the winds were creating this the other night...



RH77

[Lug_Nut]

Originally Posted by Peakster

If I wanted to average 50mph on the highway both ways, what would be the best driving technique in strong winds? Doing 50mph both ways? or say 40mph with tail wind and 60mph with headwind?

The 40/60 will not average to 50. For the sake of argument (and easier math) make the one way distance 60 miles. It will take 1.5 hours out at 40 and 1 hour back at 60 for 2.5 hours total for the 120 miles, an average of 48 mph.
To average some desired speed at some speed out and a different speed back it is necessary to use ratios. At 40 mph out (4/5 of 50 mph) the speed back will need to be 62.5 (5/4 of 50 mph) to average 50 mph. 62.5 mph is 1.5625 times faster than 40 mph. The air drag increase will be that speed increase squared or 2.44 times the air drag.
A 10 mph tail wind at 62.5 will make the "air speed" 52.5. A 10 mph headwind at 40 mph will make an "air speed" of 50 mph, almost an equal trade in air drag.