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DISCUSSION => General Topics => Topic started by: JoeDellio on April 26, 2009, 06:00:22 PM

Title: Goin on an 1100 mile road trip, will the sunroof tilted up give me better MPG?
Post by: JoeDellio on April 26, 2009, 06:00:22 PM
My bad, I meant the sunroof.


1100 mile trip from Tampa FL to Cleveland OH. I was wondering if the spoiler tilted up would give better MPG than it closed completely. Im leaving tuesday morning, thanks for any info.
Title: Goin on an 1100 mile road trip, will the spoiler tilted up give me better MPG?
Post by: 1991 E30 M42 on April 26, 2009, 09:51:23 PM
downforce = drag, so no it will not give you better gas mileage, close it all the way, leave your windows up and don't use your a/c for best mileage, the next best thing it roll your windows down with your a/c off
Title: Goin on an 1100 mile road trip, will the spoiler tilted up give me better MPG?
Post by: renfield90 on April 27, 2009, 12:03:03 PM
At higher speeds, it is actually better to keep your windows up and use the a/c. Having the windows open even a little creates a huge amount of drag. Use the lowest blower setting you're comfortable with.

Are you doing the trip in one shot? I did a 1000 mile trip in one shot...even doing 100mph for about an hour in a really, really desolate part of New Mexico (passed no cars for over half an hour, got passed once) it was around 14 hours. By the end I was fighting to stay awake.

It didn't help that one of my pit stops was around half an hour though...chose a town that made you drive a few miles away from the freeway to get to all the gas stations, fast food joints, etc.
Title: Goin on an 1100 mile road trip, will the spoiler tilted up give me better MPG?
Post by: BraveUlysses on April 27, 2009, 12:18:42 PM
Keep it closed.
Title: Goin on an 1100 mile road trip, will the spoiler tilted up give me better MPG?
Post by: JoeDellio on April 27, 2009, 10:52:45 PM
Quote from: renfield90;70887
At higher speeds, it is actually better to keep your windows up and use the a/c. Having the windows open even a little creates a huge amount of drag. Use the lowest blower setting you're comfortable with.

Are you doing the trip in one shot? I did a 1000 mile trip in one shot...even doing 100mph for about an hour in a really, really desolate part of New Mexico (passed no cars for over half an hour, got passed once) it was around 14 hours. By the end I was fighting to stay awake.

It didn't help that one of my pit stops was around half an hour though...chose a town that made you drive a few miles away from the freeway to get to all the gas stations, fast food joints, etc.


Hittin it in one shot, yes. I saw the myth busters about the windows up and AC on. Im gonna have to use my AC in at least the southern states. I didnt know if the sunroof tilted would act as an airfoil like on a semis roof. Time to put the car to the test with 246,000 miles.
Title: Goin on an 1100 mile road trip, will the spoiler tilted up give me better MPG?
Post by: BraveUlysses on April 28, 2009, 09:26:08 AM
Quote from: JoeDellio;70945
Hittin it in one shot, yes. I saw the myth busters about the windows up and AC on. Im gonna have to use my AC in at least the southern states. I didnt know if the sunroof tilted would act as an airfoil like on a semis roof. Time to put the car to the test with 246,000 miles.


Well unless you're towing an enclosed rig, a roof airfoil wouldn't exactly do much for ya, would it?
Title: Goin on an 1100 mile road trip, will the spoiler tilted up give me better MPG?
Post by: bmwman91 on April 28, 2009, 10:14:49 AM
Quote from: JoeDellio;70945
Hittin it in one shot, yes. I saw the myth busters about the windows up and AC on. Im gonna have to use my AC in at least the southern states. I didnt know if the sunroof tilted would act as an airfoil like on a semis roof. Time to put the car to the test with 246,000 miles.


Try to time your departure time so that you go through the hottest states at night?
Title: Goin on an 1100 mile road trip, will the spoiler tilted up give me better MPG?
Post by: renfield90 on April 28, 2009, 11:34:15 AM
The Mythbusters test was flawed and lacking in a number of ways. But generally, at highway speeds, it is more efficient to keep the windows closed and use the a/c instead.

My last road trip to San Diego in the Celica, I drove back with the windows closed and the blower on the first or second setting. I got mileage numbers I haven't seen in years. Not coincidentally, it's been years since I did a roadtrip that long with the windows closed.