So I have not inspected it myself. I will when I take the ride home from work today. But since I've had the car, I guess sub consciously, I put the rear sun shade down when I open the windows on the highway. I've noticed it moves so much with all the wind and was afraid it would rip. Any thoughts? As I'd rather just leave it up for the most part.

 

Never use mine. Just figured it might become one more thing that rattles. I would be interested in hearing why others do use it.

 

Use mine up all the time when parked at work always facing the sun so not subject the dash to the extreme UV/heat.
I almost never highway/freeway drive +45 with all the windows down anyway so....no I don't have the problem.

 

If I drive with the windows open, I put it down.

 

I like it when larger SUV's get behind me at night. Up it goes... Works very well. Otherwise, don't really use it.

 

I employ the shade from April until October in order to keep the blazing middle Georgia sun from dry rotting the upholstery on the back seats and the parcel shelf, and off the necks of my back seat passengers.

The only cars I see rolling with the windows down during the hot part of the year in this miserable climate are those with broken air conditioners.

 

Hahah I feel like everybody is just asking me in their own way, "Why the heck are you driving a new car without the AC on in this heat" ... really idk I just like the breeze and fresh air. Windows are always up and close in the winter, bugs me.

And the point of driving on the hwy, closing your windows past 45 mpg. Is there a reason, like drag from the air coming in? I'm sure there is, but does it matter that much?

 

Ditto on both these counts for me. The only time I lower mine in the summer is at night.

 

Only matters with MPG. Open windows create drag at freeway speeds that more than offsets the power used by the AC compressor.

This was not always true. Up until around the 1980s, AC compressors were not very efficient, and required more energy to operate than the open windows wasted.

I used to keep my windows open during the winter months down here in middle Georgia (temps often in the 50s and 60s), but found the inside of the car got dirty much faster with the windows and roof open. Lots of trucks hauling everything under the sun on roads around here, and many do not cover their loads completely.

But open windows are not an option in middle Georgia during the hot half of the year, where the air is usually very humid, there are bugs by the millions, and the daily high is usually in the nineties or worse.

 

Ahhhh I love getting school with some knowledge from the wise!

What about power though? Would having the ac on take away from power while driving?

 

Actually I have allergies/sinus issues so I find myself with the windows up most of the time. The time with the window down would be when the dog is using his ram-air nostrils. I also have the system set to cabin re-circulate to avoid all the excessive pollutants that the bigger trucks and such emit especially when powering up the many hills around here.

 

Of course - but not nearly as much as the increased drag from open windows. Somewhat dependent on speed of course.

 

Good answer. At speeds below 30 MPH, window drag should be minimal, while the power used to drive the AC compressor might have a tiny effect on power to the drive wheels.

At speeds over 45 MPH or so, the issue is more clear - the drag of the open windows at higher speeds will be greater than the power required to run the AC compressor.

Of course that is assuming travel on fairly level roads. When we consider steep climbs or steep downgrades, the issue is more complex, as steep climbs require much power from the engine, while steep downgrades require no power from the engine.