mpg lost with open sunroof while driving on highway

Really ??? No kidding .....

Of course you did ... you ruined the car cf ... in other words aerodynamic design ...

Read up! At highway speed you are (in most instances) better off using AC than opening ANY windows including sunroof.....

If it is not self evidenced just search this site there are many thread about this.

 

I'm going to have to disagree a little here. The sunroof will obviously hurt mpg when opened at highway speeds but the A/C can hurt even worse if the car is not precooled or if you are making a short trip. The A/C can cause a 10mpg drop for the first 10min or more. Driving with the windows down is not nearly as bad. So for short distance driving I would roll down the windows. For longer trips I would use the windows cracked "flow through" technique in temps below 90F. For long trips or temps well into the 100s you should just say to hell with mpg and turn on the A/C!

 

Here in Portland, when the sun comes out I open the sunroof. Vitamin D trumps mpg.

 

What's that 3 or 4 days a year?

 

We count a good six or eight days of summer in July and August.

September now... we don't tell "outsiders" about that. September remains a closely guarded secret.

 

"If summer falls on a weekend this year we'll have a barbecue"

 

I feel for you... but really the sunroof puts sunhine on you ??? guess you are sitting in the back seat ???)

 

It just depends on the direction you're driving and the angle of the sun. It was shining on me today. It felt nice.

 

Portland weather forecast system.

1: If you can't see Mt Hood it's raining.
2: If you can see Mt Hood it's going to rain.

I still think it's one of the nicest cities in the US

 

Why, thank you! I rather like it here.

 

you give me a good idea for a trial. It is so hot here...the A/C is always in the on position. But in the morning...I could probably window-it until the warm up cycle completes. Our low temp is mid 70s. Now time to try it.