just consider slipstream and dirty air basically the same. both reduce drag. you want that in a straight but not in a corner

Thinking about Jeremy Clarkson's Atom face is much better than thinking about his O face!

Fun factoid: the car in front also benefits from having someone in their slipstream, as it presents a longer body to the air and cuts the low pressure area immediately behind them. It's most prominent in NASCAR where the cars run bumper to bumper and can go faster in pairs than they do solo. If you ever watch inline speed skating they work together in long packs which dramatically helps everyone in the pack.

Seriously can't wait to see 2022 car race.

First moment I, non-native English speaker, heard "air, like water, is a fluid" I nearly spat my tea, before I could remember that "fluid" and "liquid" are different terms. Damn you, linguistic barrier! On the other hand, I belive comparing air to water is the best way to explain drag and other stuff like that to anyone of any age who have expirienced swimming. What an improvement over the years though! When I saw the title and that it has been posted minutes ago I was wondering, I could remember you already covered it an earlier video. But comparing them know, what an astonisihing progress you made!

I think it was also worth mentioning the fact that being in dirty air reduces the overall car performance. The main issue is that chasing closely a car ahead means that the average temperature of the air you'll be facing is higher than what should be, so this will lead to an easy overheat of your tires with subsequent excess degradation or formation of graining. I'm not sure about this, so I ask our lord and savior Chainbear's opinion, but I think that dirty air may not be great for engine performance. I guess that oxygen concentration in free air is a bit better, and surely the decreased air pressure in the wake will make the engine suffer a bit, although the presence of the compressor might make up for this effect.

This video summarised in about 10 words: Dirty Air - No Downforce --> Understeer/Oversteer --> Slower Slipstream - No Drag --> Faster Top Speed

This would make excellent physics class material 😁

2:49 which is why in aerokit days (2015-2017), sometimes you see Indy cars running asymmetric wings on ovals.

Chain Bear: air particles all around Me: air all particles around

3:26 Fun thing is, the drag coefficient of a cube and an F1 car are almost equal, so if they have the same frontal area, velocity and go through the same density air, the drag force would be about the same

I'd like to have been a fly on the wall at some of the teams aero department meetings. Specifically when discussing how they can create extra turbulence behind the vehicle under the incoming regs. Deciding on whether it is worth balancing the downsides to the own cars by creating that turbulence Vs the negative impact on following drivers looking to pass improving their chances for better places.

This video is basically my dissertation project without the maths, how nice everything is without the maths 😂

This is very noticeable watching onboard footage and keeping an eye on the car's front antennas. The antennas are very still on the straights and go wild when following another car on the corners or mid-overtaking, when the driver change lanes and go from the slipstream to clean air - in-between there's heaps of dirty air and the antennas go crazy!

This explains the basic theory well but I wished there was more practical discussion. What confuses people is why are we told that following another car slows you down if they're intentionally following each other during qualifying laps. It sounds contradictory and the nuances of it are subtle, complicated, and rarely ever explained in the media.

When you're so early you can't autoskip the sponsorship yet

Great video explanation. One part you got slightly incomplete is at 8:17, the reaction force is only a 2/5 slice of the downforce. most of the downforce is made by suction of faster air running underneath the car, not by reacting to air going up. Lower pressure sucks the car onto the road, not just because air is being pushed up. The diffuser as a concept does not need air on top. just air flowing underneath. In that case the only opposite reaction is the cars suspension.

7:23 love that the bus is so recognizably a Transport for London Wright New Routemaster

This year is my first season watching F1 properly and this is *exactly* the question I've been asking in the last few weeks because the commentators have never bothered to explain it. Thank you so much! Excellent video, and an extremely clear explanation.

7:20 It's definitely not linear in case of tíres. The friction coefficient decreases by adding more normal force on the tire. This is the basis of many things in vehicle dynamics

Thank you! I’m relatively new to F1, and this has been one of my biggest questions. Solved!

I love your old janky version. I have shared that with so many people to explain the effect. Glad you have re-done this though!

Excellent video Chain Bear. This is a subject I felt I understood pretty well, but I still leaned plenty. Your explanations are clear and easy to understand, and moreover enjoyable!

3:19 a rare insight in Ferrari's technical drawings for the SF1000

Great video, only one thing I would correct; the friction of a tire is non-linear. If you push twice as hard you do not get twice the lateral force, this is the reason why you want to reduce weight transfer since what you loose on the inside tire is not gain back completely on the outside tire.

The slip stream is not lower density, it's lower pressure. Think of air in a tyre. If you warm it up, the air pressure goes up, but air density goes down as it expands. Pressure resists the compression forces on it, NOT a higher density of air. The car in front is pushing against higher (still) pressured air. The car behind is passing through air moving at speed which is lower pressure against it's front. Pressure is directional and is measured via force applied over surface area. With less pressure from the front, you have less force from the front going against your car. Density is just the amount of air occupying a certain volume of space (which is actually the same for both cars). The air density remains the same for the car infront and the car behind, the pressure though is different. One has air compressed against it, raising the pressure by a lot, the other has air moving forwards from it, so it's like encountering a tail wind.

Thanks for the video. If you're in the market for a new video idea I would like to request one. Could you show some of the likely outcomes of the 2021 Russian GP had certain drivers pitted at different times than they did. For example, had Lando and Charles pitted for wets when Lewis did (or the lap before) based on their existing lap times.

Always love your videos. My ONLY slight observation is you might want to use a sailboat and rudder instead of a raft. Paddle boat, speed boat, submarine, jet plane, helicopter, anything like that use the medium they're in AS their propulsion. A car uses friction against the earth to move through air, and a sailboat uses friction against the wind to move through water, so I feel like they may be the closer cousins because each of them use an independent propulsion to move through a medium they're in direct opposition to, if that makes sense. Doesn't have anything to do with your explanation, because you didn't mention that the oars would be causing their own little wake patterns separate from the raft. Just a thought I wanted to share. Thank you for the wonderful content!

Stuart another well explained video, something I’ve not seen before on UKposts. I’ve decided to support you on Patreon throughout the 2022 season with the new regulations. Keep up the good work and well done.

Yes! I’ve been waiting to learn this properly. Thank you!!!

Your videos are so exciting, thanks for all this Contents. How do you do your animations and video representations ? Continue like this, you're the best !

Funny, I always thought the rear wing was meant to create traction/grip on straights as well. Because of that notion, I was always confused with DRS, as I thought the thin air in the slipstream would reduce traction, so reducing traction even more by opening the DRS didn't make a lot of sense to me: why was everyone so concerned about creating traction with floor effects, rear wings, soft tyres and so on if then the best way to gain speed was to reduce drag (and therefore downforce) as much as possible? I guess there is a point of diminishing returns in the traction/speed proportion, and getting extra downforce exclusively for curves explains many things. Now DRS makes a lot more sense. Your videos are awesome ^^

I’ve been wanting to understand this. Thank you. Love from 🇿🇦

And suddenly I am now remembering the song you made about this very topic

Slipstream = builds speed on straights Dirty Air = robs downforce while cornering Easy

Correction to 3:24 Assuming the same cross section area the cube would have a slight advantage over F1 car in terms of drag. Cube has drag coefficient of about 0.8, and F1 car has a drag coefficient of about 1. For context normal cars have a drag coefficient of about 0.35

7:20 that is true only when the friction coefficient stay the same, but tires are load sensitive, meaning that when more (vertical) load is applied on them, their friction coefficient starts dropping, so the relationship is not linear for tires, it is digressive. Example: You have 1000 N load initially on a tire, with a friction coefficient of 0.4. This means you have 1000 N * 0.4 = 400 N of friction force. You increase load to 2000 N for the same tire (via generating downforce), but the friction coefficient dropped to 0.3. This means you have 2000 N * 0.3 = 600 N of friction force, not 800 N, which is the case when friction coefficient stays constant (at 0.4 in our example).

Could you do a video on seamless sequential gearboxes? I know there isnt a lot of info out there, but i am curious what you know/find out.

You took a long time getting to the simple fact that slipstream vs. dirty air is straight line vs. cornering. The only thing I didn't like about your description was describing drag as "pulling the car back" rather than resistance in the front, which is what it is. This is similar to NASCAR rubes who don't understand elementary physics thinking that drafting sucks the front car back rather than the thinner air allowing the car behind to accelerate faster. The buffeting of the rear car as he pulls out to pass starts slowing him down, but the buffeting of the front car as the rear starts to pass does not slow it down until the passing car is in front of him causing air to pile up in front of his car. There's a great deal of misunderstanding of how aerodynamics work for those who lack a good education. Thanks for your instructive video.

Great video explainer this. Could you do a video in the future about why the rules on how many components (such as a ICE or PU or gearbox) are so restrictive that everyone has to take penalties in the year. I understand that without any limits then the costs will massively inflate as teams use highly performant single use components but why are they so restrictive that it seems no-one can stay within the limits? Why not relax it so that people can realistically stay within the limits while being restrictive enough to keep costs reasonable. Thanks!

Clearest explanation of these phenomenon! Thank you always Chain Bear!

you can also think about it this way: downforce produces corner speed but slows the car down in a straight with slipstream you reduce downforce and drag helping reaching higher speeds in straights but slowing down the car in the corners with less downforce

Aerospace engineering here: air density doesn’t change. Air is pretty well characterized as incompressible (constant density) at sub transonic velocities (

Thanks man..... was having this doubt in mind but never got satisfying answer.... although I knew that concept but thanks for elaborating so nicely

I think that a good example for dirty air in water as discussed at 8:30 would be the swimming in whitewater. Whitewater contains more air than unmoved water and hereby reduces its density and therefore the lift and probably also the counter force created when trying to paddle with your hands. Therefore it is almost impossible to swim in whitewater without other tools.

500k subs! Congrats Chain Bear!

TLDR: Slipstream and dirty air are the same thing. It's good on a straight line but bad in a corner.

and here i thought dirty air was what happened when the silly vortexing wild air being forced *around* the slipstream bubble crashed back into the middle of the track as the low pressure zone disappated, like the eddies in the wake of a boat behind the smooth laminar flow of the immediate wake. I hadn't really considered the effect on cornering.

Great video, keep up the great work!

For those who are wondering why we need down force So basically while cornering the necessary centripetal force comes from friction between Tire and road which is the function of car weight and coefficient of friction between Tire and road but considering the car velocity the necessary centripetal force is not enough just by relying on car weight and hence a down force is required to Artificially increase the weight of car and hence increase the centripetal force so car can take smooth tight turns and does not undergo understeering condition

I would watch Formula Cube imo

The quality in this video are amazing! Thank you for providing us such great educational videos for free!

Nice touch with the calculator numbers, Chain Bear :)

This also applies to DF setup strats. If u want to chase, a slightly higher df is good, if u wanna lead lowered df is good.

What font are you using it's amazing

Slipstream may be exaggerated to mean a vacuum created by the front fast-moving car (as it takes time for the surrounding air to fill the displaced space), thus staying in the vacuum allows for higher top speeds due to less drag. The term focuses on "the lack of." During cornering, downforce is to some degree reduced by a drop in pressure, however, that's only a small part of the "dirty air." More importantly, "dirty" air includes turbulence and vortices created by the front car (and staying on the track -- it takes time to dissipate or going back to a uniform state -- think of it as small wind streams tangled in different directions). I would not say the two terms describe the same thing in two situations (like in the comment by FullOilBarrel). Because "dirty air" hurts more than simply providing a low pressure, as explained.

I asked this question previously: would it be possible to reduce dirty air / turbulence through direct regulation of the car's wake? Consider it an extension of the limits to car size: as well as restricting the length, width, and height of the car (i.e. the physical space the car takes up), put a physical, measurable limit on the amount of turbulent air it produces (i.e. the broader aerodynamic space the car takes up, defined at a certain distance back, or maybe set limits at several distances and several speeds).

He managed to use Sochi as an example of an overtake, what a season :0

Using water as an example again, slipstreaming can also be thought of like a small car tucking up behind a big truck as they both go through a patch of high water. The truck pushes all the water out so that it’s shallow enough, albeit briefly, for the small car to go through. Dirty air would be as if the truck started turning through the water. The car needs consistently shallow water to be able to continue to keep up, but as the truck turns it disrupts the flow of shallower water for the car, making that task more difficult. I figure that just about everyone who’s been driving more than a year or two on public roads (at least the ones in the US lol) has experienced that scenario at some point so I figured I’d toss it out there.

Nice ending! That's new to me.

As a new F1 fan I am thoroughly enjoying your videos. Thanks👏👏

this is a very good explanation about the difference. thanks so much for that!! slipstreaming exists in every racing discipline and so does dirty air, I guess. however, is dirty air just a worse problem in F1 than in Touring Cars (for example) because of how the wings are designed? (vortexes and other things you explained)

In your TLDR, you got it the other way around, you wrote that drag is good for straight line speed and that downforce is bad for corner speed

Doesn't the messy, disruptive air mentioned at 9:05 also cause problems for the follower on the straights? Maybe not in speed, but maybe in stability and thus handling of the car?

Brilliant video. Please do more such videos.

It’s basically the space behind a f1 car that doesn’t have enough air or a low pressure region. In straight lines it’s called slip stream as it reduces the drag on the car. On curves n turns the same air is called dirty as it reduces the downward force needed to grip the car.

this is the best explanation I’ve seen. Watching F1 will be much more exciting knowing this. Thx

Aerodynamics, [ and to a slightly lesser degree hydrodynamics ] is one of the most complicated and difficult things to understand and control. To some extent a racing car is analogous to an aeroplane. In the latter case you want to generate LIFT. To do so you inevitably create DRAG, and aeroplane design is basically the problem of control and balance of WEIGHT which is in opposition to LIFT, and PROPULSION FORCE which must oppose DRAG. For a car, LIFT is substituted in the mix for DOWNFORCE, otherwise the problems are the same. In practical aerodynamics the wind tunnel is the most useful tool, because calculation is so difficult. Wind tunnels rely on an input of smooth air, which the object under test disturbs, leaving a turbulent wake. In the case of car racing, only the lead car experiences anything approaching smooth air, those following are faced with violently turbulent air. Ordinary drivers on public roads which are unpaved become intensely aware of " eating the dust " of the vehicle in front in dry conditions, or, on paved roads in the rain, an opaque spray. The basic shape of a racing car is not conducive to having low DRAG. In fact in the case of the wheels, it's desirable to create drag forces around them for air cooling of the tyres. In the 2022 machines there appears to be a new emphasis on creating laminar [ that is smooth ] flow over the tyres which will reduce DRAG but decrease the cooling effect. Like I said aerodynamics is a difficult subject - every change affects everything else. If race car design follows the example of fighter jet design we can expect introduction of more variable geometry, and all of it computer controlled !

Great videos mate I appreciate you.

cute bear chain bear. GOOD VIDEOS. NO BS. NO DRAMA. JUSS PURE FAXX AND INFO. GOOD ILLUSTRATIONS, LOVE'EM

Now where can I get that Chain Bear soda shown in the outro?

Turbulent (dirty) air can still cause drag but not provide good even downforce. Think about if you had downforce on the wrong side of the car (left instead of right, forcing a lockup on the left wheels when you're turning left - left wheels spinning less than right wheels). Slipstream is lack of drag due to the relative movement of air going in same direction (think about having a tailwind). Slipstream can be dirty or clean. They're trying to clean up the slip stream's dirtiness in the new F1 cars for 2022. Air resistance is required for downforce (in excessive of weight), which essentially is drag. Clean drag vs dirty turbulent drag - you can have the same amount of 'drag' that is dirty and horrible if it's still spinning in vortices and not still, putting uneven downforce all over, vs nice clean still air ahead. Think about cross winds that are blowing in gusts instead of a constant stream. One moment it's pushing you to the side, next moment it's not. You've counter steered only to find you need to steer straight again... over and over. That is the effect of dirty air. Tail wind may reduce drag, but overall, is different from dirty air, as it is smooth. Regardless how you drive, straight or around corners - you don't want dirty air because you lose control. Less drag is fine, as long as it is clean, you can still navigate the corner at good speed. As for saying drag is not taken into account when braking, no drag = less downforce on your tyres = less friction when braking. Therefore, DRAG is important for braking - for the downforce, not for it's stopping power (at higher speeds it does slow you down more, but more efficient downforce should be prioritised over 'drag' in that sense... drag is an unwanted but necessary side effect when trying to get more downforce, the issue is finding the balance of downforce for the amount of drag you're willing to compromise) Mercedes have longer cars, allowing more downforce for the same amount of drag overall, compared to redbull that has the shortest cars, who rely on their shorter wheel base to navigate corners better, hence requiring a higher rake and more drag to produce the same amount of downforce. Can be seen in the straight line speed difference between the two cars. Verstappens' style of driving suits a shorter wheel base as he does micro turns rather than one big smooth turn, a shorter wheel base allow more controlled oversteer so he spends less time 'turning' and more time 'driving straight' - which is better for tyre wear, this allows more controlled corner over taking, and allows you to take narrower inside lines when at turn 1 side by side battles, or outside lines with later apexes to get on the power earlier as it is a much slower but sharper turn --- you early brake outside lines for later apex and faster exits. Hamilton's style of driving suits longer wheel base where he can decide when to brake a lot more comfortably, and win on straights and inside line entry speeds as his braking distance is shorter. He also has to take a longer curve exit due to under steering, so MUST win on the entry speed when on inside line so that he is ahead and able to make the turn to the full length of the corner. His car is too long to hug the inside line of a turn at speed and would have to slow dramatically if he's ever pinned side by side. (rules of current F1 racing favors inside line late braking as it gives advantage to whoever is 'in front' when turning... that is why outside line drivers always have to give up the position and take a riskier turn into late apex... and hope for a switcheroo with their faster exit. - You late brake inside lines for faster entry but slower exits. It's also the reason why Hamilton hit Verstappen at silverstone. He couldn't steer further into the inside after having to brake so late when verstappen forced him to go behind him to take the inside line very late into the straight and his longer wheel base understeered (Mercedes car need the full length of the turn at speed, so he would've edged Verstappen off the lane even if there was no contact, unless he slowed down which is very hard to do whilst turning as braking can lock up wheels and still send the car into verstappen). If verstappen followed his usual racing line to take an early braking into a late apex, hamilton charging down the inside would be on his line, and per FIA rules, he can not take the line, so he had to take an outside line that put him at risk of Hamilton crashing into him. If Hamilton was in a redbull car, he can probably take the inside line turn, but he wouldn't have had the straight line speed to get there before verstappen closed it off. So for the same drag, mercedes cars have more downforce, but when it comes to dirty air, the uneven downforce applied is also amplified, that is why mercs HATE to race behind other cars compared to redbull cars that can follow in dirty air as their reliance clean drag for downforce is not as much There's a bunch of fakers pretending to be aerodynamics engineers or mechanical engineers what not, we can't prove what they do, but the lack of detail in their reasoning is appalling, so take what you will with a grain of salt.

I have had this question for so freaking long. You're the man!

This is the problem, dirty air and slipstream negate each other from corners into straights and vice versa, the cars fall so much behind in corner that it barely makes the time it lost due to dirty air in the slipstream (net time gain= 0 or negative mostly) if the corner leads to a straight which is why they brought in DRS to make slipstream more effect but DRS has its own issues. All aboard the DRS Train!! choo! choo!

Expecting a video about how Ocon finished a race with a single set of tire

Could you make a video explaining what they mean when they say a car "Is still live"? I heard it's something about electrical charge and people are not suppose to even touch it and I really don't understand how that happens. Thanx in advance!

So perfectly explained! You're awesome!

what i like the most about f1 is their criativity and the fact that the innovations they create will be commercially available when it becomes cheap increasing safety and driving pleasure it's awesome

why is chain beer my favorite youtube channel but others not?

Alternative Tl;dw - Air generates both downforce and drag. Car in front removes air from car behind.

Future video idea: take how the F1 games give the drivers stats such as pace, race craft etc… and apply it to the cars with categories such as speed, aero, handling, braking etc… we all know the cars are all unique but I’m interested to hear how you would score the 10 different vehicles on the grid.

Now I want F1 cubes.

been confused about this since James Hunt was banging on about it in the 90s

Great explanation 👍

Ohhh I like the new outro graphics

Hey, Stuart, this question is coming to me as I’m watching the podium ceremony after Istanbul. How is it that drivers can go an entire race on a single set of intermediates as Ocon just did?

This is an incredibly useful video. Great job!

is that Vettel parachuting?

Great remastered topic

Brilliant. Crystal clear explanation.

Nice video. Appreciated!

3:20 Is the car moving forward or the road moving backwards? :P We need a separate video explaining that.

3:18 holy shit, man went crazy and built a full SF1000 model for our entertainment and education

The 3D art in the credits is cool

I remember when I first started watching F1 this particular question was something that definitely intrigued me. At this point I've gotten the gist of what the difference is, but I hope this video can shed even more light on what I already know.

great video as always

Thank you so very much. Although a simple problem but this has been bugging me for a long time.

such a good channel keep it up i enjoy ur videos

If downforce is proportional to the cars speed wouldn't it be better to just make the cars heavier to handle to corners better? Since in a straight line the wings would create more force when you don't want it and not when you do

Teams must next year build cars that are better for others to overtake.