Hi guys,

Just curious...almost everyday on the way to work/home, and almost all other times unless it's raining I have my drivers side window down, as I like the fresh air. I keep it down while I'm on the highway at speeds of 75mph+, I was just wondering if this is ok to do? First off, am I damaging any part of the rubber around the window? Does it give more of a chance of dirt flying into the track? Also does it greatly effect gas milage, or excessive engine strain? I'm pretty sure I've read somewhere saying that you actually save more gas by running the AC with windows closed then windows down on the highway...Anyone know the difference? Is it significant?

While I'm on the topic...Is ok to close/slam a door with your window down? For example I drop someone off and they had their window half down, and they just slam the door shut? I always feel like it's going to fall down, or possibly shatter?

Thanks!

 

It's fine don't worry about it. As far as gas mileage, it's been proven with a ford explorer that above 45mph all windows down uses more gas than the ac. Not sure what the critical speed for the G37 is but it should be around that figure.

 

I do not believe you are damaging anything on the car, as it was probably designed with those parameters considered.

The tempered glass on vehicles is actually pretty strong and slamming the door will not affect the glass and probably not the brackets and hinges inside the door. Sounds like a job for Myth Busters.

Gas mileage is affected. Freeway speeds will create more drag with windows down probably not noticeable though.

With windows fully down a circulation of air is created in the cabin reducing air flowing in or out, some people think the back window will act as a parachute, this is false. most air will not come into the cabin unless you stick out your hand.

No engine strain, possible transmission strain due to extra load on vehicle from drag, might be impossible to test though.

You might be damaging your hearing though, at freeway speeds cars and trucks sound much louder and also produce noise from turbulent winds.

 

Window mid or fully down and door shutting.. you shouldn't have a problem.

Are you losing gas mileage.. definitely. 1mpg? 2? No one knows.. no worries on the driveline, but you will see a dirty headliner and other parts over time, as airflow tends to be the same coming through the cabin. My G35 just turned 111k.. and I'm the same way, love fresh air, and there are some definite patterns you can see with 'dirt' on the headliner. I'm also not one to go crazy vacuuming the roof, so it's probably on me.

Normal maintenance, doubt anyone would know. No worries on the rubber on the door either, unless there was physical trauma from something.

 

Windows - nothing is affected by closing the door with the window in any position

gas mileage - Our engineering department did a project on this when I was in college and there was a slight difference with windows up+AC vs windows down but it was so negligible that you would never notice. I like having the windows up when I am driving highway speeds or faster personally

 

If you got sunroof, I think it would better to roll up all the windows and open up sunroof.

If you really enjoy fresh air, you might want to consider trading ur car in for a convertible. Not sure how fresh air when driving especially when trailing 4 x 4 truck or suv front of you.


Other ppl do this to with my car, they slam the door when exiting. I think ppl don't realize you dont' need to put that much force to shut the door. I never understood why ppl do this. They slam it like spiking volleyball.

 

Same Here. I hate when people slam my door. but I do notice that most people who do slam my door have an older car that requires more force to close.

 

^ +1 my gf SLAMS the hell out of my car doors every single time she gets in my cars. The G doors take it bad, but the trunk is worse, when she SLAMS that I feel like my G is going to break in half. I don't think she's happy with my mistresses.

 

Haha funny thread, dont think about it too much, the only thing is mpg but thats not a big problem.. I just had the sunroof open on the freeway and it felt like it slowed the car down faster than with everythin off so thats the only negetive.

 

If you want some fresh air by all means open the windows and enjoy. Gas mileage is not going to suffer to the point that you would notice. Only drawback is the dirt that will get into the cabin. I like to drive with all of them open and the sunroof.

 

At normal city/highway speeds, the AC will always affect your mpg more than windows-down motoring. Other than dirt, you are not putting any noticeable stress on your car with windows down.

 

there was a mythbusters episode about this

 

at the very least, you are creating aerodynamic drag which is multiplied the faster you go. Of course, one window, on an especially aerodynamic car, probably won't make a really noticeable difference.

As far as closing doors with the windows open; I would avoid slamming the doors too hard. When the window is in the frame, it is much more secure and probably doesn't strain the other parts as much. Again, probably not a big deal, but it couldn't hurt to be a little more careful.

also, i'm not a mechanic and I'm just pulling stuff out of my a

 

in terms of damage.....no damage.

in terms of drag.......having your window completely open does create drag....however if the window is only slightly open....i dont think it will create any drag....very little if anything, nothing to worry about

however....as an alternative....try opening ur sunroof....or venting it.