Opening windows to help with braking?
Posted by NYCThrowaway2604@reddit | askcarguys | View on Reddit | 83 comments
This may be a really stupid question, but could it possibly be worth it to open your windows while braking to increase drag and reduce wear on your brakes? (Then roll them back up once you start accelerating again.) Even if this only makes a 1% difference, that's potentially hundreds of extra miles until you have to get new brakes. Like the poor man's version of an active aero spoiler.
Am I just autistic for even thinking about this?
Just_blorpo@reddit
Sometimes it’s intriguing to think of ideas like this from a strictly scientific point of view. But it’s also important to consider what the actual experience would be like.
krazul88@reddit
Have you considered jumping out of the car just before braking? This would reduce the weight of the car by at least 300lbs, thus reducing stopping distance and wear on the brakes.
Longjumping_Pilot840@reddit
May as well drive naked to save the weight of your cloths to reduce wear and tear on the brakes…
Remember to unbolt the seats you do not need too as those are just extra weight.
Please think about the practical aspects of this- brakes last 50-80k miles and are designed as a wear part. Windows are not designed to be played with constantly.
Do us all a favour and look up and ahead and plan your braking better if it matters so much and try to lift off a coast rather than accelerate to brake.
NYCThrowaway2604@reddit (OP)
I'm one step ahead of you, I already drive naked
Longjumping_Pilot840@reddit
Shaved head too I hope for the aero gains?
NYCThrowaway2604@reddit (OP)
And weight reduction
Ok-Situation-9199@reddit
Argentius99@reddit
This is one of those “rounds to zero” things , not worth the effort (and window motors )
Active aero is a real thing - my car does some stuff with grill shutters, right height , what have you - but the window thing is goofy.
If you actually want to reduce wear on a … wear component , biggest thing is lift and coast , and, anticipate the lights.
if you want to go nuts, hypermiler forums have all kinds of crazy ideas.
NYCThrowaway2604@reddit (OP)
Thanks, I'll post my idea on one of those forums
Major_Lettuce_6748@reddit
Ja, die Aerodynamik des Autos wird durch das herunterfahren aller Fenster gestört und der Luftwiderstand erhöht. Das wird aber kaum einen spürbaren Effekt haben. Dagegen musst du ja auch wieder halten, dass das hoch und herunterfahren Strom verbraucht, was wiederum den Benzinverbrauch wieder minimal erhöht. Und die Fensterheber sind nicht für unendlich Zyklen ausgelegt und werden schneller kaputt gehen. Spätestens mit Kauf neuer Fensterheber wird jegliche Ersparnis zunichte gemacht.
NYCThrowaway2604@reddit (OP)
Not if your windows are hand crank operated...
Max_Downforce@reddit
It's stupid. Stop driving and take the bus.
NYCThrowaway2604@reddit (OP)
Ok, I'll open the window on the bus every time the driver brakes to help him slow down
Consistent_Law_3857@reddit
Put your hand out the widow like you're signaling "stop". Got to be a few watts. Probably not noticeable, but fun.
GigaChav@reddit
Correct
robindawilliams@reddit
The idea isn't totally off because any drag does in fact slow the vehicle but the scale of the forces is hilariously different.
Even if you opened the windows and pushed out entire 30ft sails like a pirate ship you wouldn't likely make a meaningful difference compared to the braking forces of a car.
What DOES work is you could utilize engine braking to use the compressive resistance of a combustion engine to slow the car down, but this requires shifting the PRNDL into a lower gear which isn't very obvious on newer cars.
GigaChav@reddit
Bk_Punisher@reddit
Good bye transmission though. Maybe if the car is a manual but not an automatic.
robindawilliams@reddit
It shouldn't do damage if done properly.
https://www.uti.edu/blog/automotive/what-is-engine-braking
agingcausescancer@reddit
A few hundred miles before you have to replace brakes doesn’t save anybody any money anyways.
Tantricationz@reddit
Window mechanisms and switches are a lot more expensive than brakes 👍
turbski84@reddit
Also more of a pain in the ass to replace
Tantricationz@reddit
Truth.. I'd rather replace all 8 pads and 4 rotors than one of those stupid window mechanisms
GundamArashi@reddit
As a mechanic I fully agree. I’ll take the most pain in the ass brakes on our worst car than do anything inside doors. Big parts in tiny spaces make for an angry tech with bloody arms.
Tantricationz@reddit
Amen haha
IOI-65536@reddit
The funny thing is how much this misses the scale of how bad the windows are. From a pure pain to replace perspective I would absolutely rather replace the pads, rotors, and calipers than a window mechanism and depending on the car you could probably add the master cylinder and booster.
BJoe1976@reddit
This, plus you might be hurting gas mileage as well.
LUXOR54@reddit
Are you really concerned with gas mileage specifically under braking?
Assasin537@reddit
If you are concerned with getting 1% more life out of your brakes, I would argue you should be concerned about gas mileage as well, especially since the windows won't roll up instantly.
JP147@reddit
There is no such thing as a stupid question.
That is what I used to say, but after reading this post I have changed my mind.
zinsser@reddit
I'll try to make this long story short. During first aid training in USMC basic, the instructor was explaining how to apply a tourniquet - as a last resort, between the wound and the heart but as close to the wound as possible. (Despite what you see in movies and TV, a tourniquet usually results in the loss of that limb - unless you can get the person to a hospital in minutes.)
Pvt. Smith, the dumbest guy in our platoon raised his hand and asked where to apply a tourniquet for a head wound. The instructor told him you would just need to apply bandages and pressure to a head wound, because obviously you don't want to wrap a tourniquet around someone's neck. Smith raised his hand again and asked, "But what if it's really bleeding bad, then would you use a tourniquet?"
We were seated at rows of tables. The instructor hopped onto the front table and stomped from row to row until he reached Smith. "I want to shake your hand, private," the instructor said. "I have always said there's no such thing as a stupid question, but that is the stupidest question anyone has ever asked."
When he returned to the front of the room, the instructor said, "If any of you are ever wounded in a foxhole with that man, I suggest you shoot him. Because I don't think he believed me when I said "never put a tourniquet around someone's neck.'"
ChrisGear101@reddit
LOL
Bk_Punisher@reddit
Just open all your doors and pop the hood while braking, that should do it. 🤣😂
Chemical_Support4748@reddit
Could just drive into a wall for an immediate stop
aringa@reddit
You are wearing out excessive components to face check components that are supposed to wear and be easily replaceable.
Blu_yello_husky@reddit
Its not enough drag to help anything at all really. Thats like taking your glasses off so you can run faster. technically it helps you but not in any way youd ever notice.
I_am_not_kidding@reddit
hang your foot out of the window for max drag
UmatterWHENiMATTER@reddit
Just rev-match and downshift to decelerate... since you're so worried about brake pads.
scream4cheese@reddit
LOL
action_max@reddit
Drive with anticipation instead... ease off the throttle earlier and brake more gently.
Longjumping-Log1591@reddit
Thats really stupid, you need to open the Doors all the way to increase drag, silly goose
julianAppleby5997@reddit
We are all stupider after reading that. Thanks
Turbulent-Matter501@reddit
no. this will not help you in any way and will probably cause you to crash while you're distracted by constantly fiddling with the windows when you should be paying attention to the road and the traffic around you. do not do this.
TheCouncilOfPete@reddit
Technically this is correct as it fucks with your car's aero veeeeery slightly
advmaxx@reddit
Opening windows and dragging ones feet Fred Flintstone like is very beneficial to stopping a large automobile.
PckMan@reddit
We could try to do the math but there is no point. Aerodynamic drag is not linear, it increases exponentially based on your speed and the worst of it is at fairly high speeds, while the effect at city speeds below \~80kph (\~50mph) is negligible. Below that the dominant force is rolling resistance.
So you're basically saying that only while doing highway speeds, 80-140kph or so, you want to open the windows for a \~5% increase in drag that rapidly diminishes as you lose speed and providing a negligible amount of braking force, not even considering the time it takes to roll the windows down and back up again or how distracting it is to do this while driving.
I highly doubt there would be a perceptible difference in your brake pad life. You want to save your brake pads? Engine brake.
ozaudi@reddit
Here's a thought. Next time you pull intp your driveway just put the windows down a cost to a stop.
gheiminfantry@reddit
Yes, it's a stupid question.
AlanofAdelaide@reddit
Opening the bnnet will really slow you down
Altruistic-Rip4364@reddit
If you leave it half open it’ll slow you more
Independent_Good5423@reddit
It doesn't work like that, unless you going 200mph then yes it works
Longjumping_Pilot840@reddit
Additionally; we should all know that you use BRAKES to slow down and you take a coffee BREAK from work.
I need a BREAK from those who don’t know the meaning and spelling of basic words.
ScaryfatkidGT@reddit
Actually not the dumbest dumbquestion I’ve seen…
Poor mans active aero?
Dorsai56@reddit
This is utterly ridiculous.
1995LexusLS400@reddit
Theoretically, yes. Practically, no.
Use engine braking for this.
WhatADunderfulWorld@reddit
The answer is yes. But not by much. Not at 60. If you are going 150 then sure. But might affect the stability.
No_Independent9634@reddit
If you're going 150kmh and slam on the breaks it might help.
But if you're driving like a normal person, no. You're not going to see any aerodynamic benefit at low speeds.
gstringstrangler@reddit
*Brakes. Come on man it's a car sub😂
No_Independent9634@reddit
Where I'm from its breaks. You break your speed.
xXx_ScottiCopper_xXx@reddit
I don't know where you're from, but no... It is not "breaks". Not anywhere in this whole entire world is it "breaks". Good try though
gstringstrangler@reddit
My bad b
xenoslain99@reddit
You should just open doors when braking.
Professor_Iron@reddit
Opening a sunroof with a large drag surface could have some effect. But the side windows not really.
Also - the windows must be designed to be operable at high speeds. Manufacturers often program the sunroof to automatically close above a certain speed to avoid possible damage.
OofNation739@reddit
You could but its much more insignificant and costly than brakes itself.
You get better results from a real drag brake like a panel going horizontal to vertical.
Really its use also gets much more exponentially at higher speeds. At normal driving speeds your not doing any real favors due to how good brakes are. The real benefit of drag for braking starts at like 60mph and falls off below that.70mph to 30mph is easier on brakes.
Now if we were doing 200-60mph, drag based brakes would do wonders. The normal braking system struggles more at those speeds and wears alot quicker.
LuckyNumber-Bot@reddit
All the numbers in your comment added up to 420. Congrats!
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OkKnee7580@reddit
Just buy a brake kite like the rest of us and release it b4 u brake.
BassesNBikes@reddit
Or make some holes in the floorboards and Flintstone it.
CrucialFusion@reddit
Stick your head out the window at the same time and fully extend your arms if possible.
Beneficial-Door-3985@reddit
Nope!
theblairsmashproject@reddit
The only benefit would be nobody ever asking you for a ride again. So if you hate people, this is a win.
nostradumbass7544678@reddit
Opening the hood would work way better. Just disable the secondary latch, and pull when you're ready to stop. You could even hook up a couple bungee cords to make it self-resetting.
antidavid@reddit
Yes it would work. It isn’t worth the negligible gain. At 60mph it’s not doing much. Active aero makes a huge difference at 100+
El_mochilero@reddit
Cost to replace a window mechanism on a Toyota car/truck: $400 - $700.
Cost to replace brake pads: $75
You pick.
SandstoneCastle@reddit
Won't do anything. Popping the drag 'chute on the other hand...
Of course, you'll need to pack it again to be ready for your next stop.
LegendaryTribes@reddit
just drop it into a lower gear to provide engine braking
Ok-Lavishness-7904@reddit
Plus, it takes a hand off the wheel during heavy braking. Don’t
SevroAuShitTalker@reddit
Well no, opening the windows wont matter
However, if you dolphin your hand, you might get some extra lift
gstringstrangler@reddit
That could induce porpoising
Bob_12_Pack@reddit
Gotta turn it sideways to really slow down
gstringstrangler@reddit
This is quite literally peak auto-autism. Is there an effect? Yes. Is it worth doing? Only to feed your autism. Hope this helps
PromiseNaive2172@reddit
It would work. Open just one window in the back and the noise reverberations will drive you nuts, so you’ll apply the brakes and slow down. Even if it did reduce drag, at ~3,000 lbs that amount of drag won’t slow the car significantly at legal speeds. Regenerative braking with an electric car and one pedal driving is pretty cool though.
FourCats44@reddit
I imagine if you did it long enough a police officer would politely pull you over and ask why you were doing it.
And then probably give you a ticket for lack of due care and attention.
Technically it would create more drag it would be unpleasant in terms of noise, distracting and any gain in braking would probably be instantly lost in fuel unless you came to a complete stationary stop.
Paqza@reddit
No