Formula One Cars Are Stripping Off Paint To Save Weight

KATHLEEN DAVIS: This is Science Friday. I’m Kathleen Davis. Formula One is known as the pinnacle of motorsport with cars that can hit speeds of 230 miles per hour. Thanks to the Netflix series Drive to Survive, the sport is more popular than ever, and fans can look forward to the Grand Prix in Austin, Texas this Sunday.

For the rest of the hour, we want to focus on some of the engineering that makes these cars so special. Say you’re an engineer working for a Formula One team, and you need to figure out how to reduce weight from your ultra fast car to new minimum weight requirements. Maybe you turn to the construction of the frame of the car, or you find lighter engine parts.

But as of the last couple of years, many teams have been stripping the paint off of the cars instead to save weight and get that little extra bit of speed. Dr. Kyle Forster is a former aerodynamicist for the Mercedes AMG F1 team. He runs the YouTube channel Kyle Engineers and is a lead aerodynamicist for JKF Consultants. He’s here to break down the engineering changes made to Formula One cars in recent years, the newest in paint science, and what aerodynamic changes he has his eye on in the years to come. Welcome to Science Friday.

KYLE FORSTER: Oh, hey. How’s it going?

KATHLEEN DAVIS: Good. Good. Glad to have you here. So Kyle, you used to work as an engineer for the Mercedes F1 team. Can you tell us about what it’s like to be an aerodynamicist for a team?

KYLE FORSTER: Yeah. Well, basically the job, which some people may not know quite what it is, is to make the cars faster. And the way that the aerodynamicists make the cars faster is by changing all the little bodywork components all over the car to just get marginal gains here and there that you add up and snowball over the course of a year that progressively make the car faster and faster around a circuit, primarily by increasing the downforce, which is the aerodynamic force pushing down on the car, pressing the tire into the road, and reducing the drag, which is the aerodynamic force pushing the car backwards and essentially slowing it down in a straight line.

So obviously, being an aerodynamicist, working in Formula One is basically the pinnacle for a Motorsports aerodynamicist. And you get to do some really cool stuff there because there’s, obviously, large budgets. You’ve got a lot of really cool wind tunnel equipment that you can use. And also the computational resources are really strong, too. So you get to do some really, really good experimentation that you can’t really do anywhere else in the world.

KATHLEEN DAVIS: Yeah, it sounds really exciting. Before we get into some specifics, can you tell me a little bit about how these cars actually get made? I imagine it’s not like you can just go to your local auto parts shop and pick something off the shelf.

KYLE FORSTER: Yeah, no. So these cars, basically every component on them is bespoke. Obviously, across the grid, there’s some standardized components and some things like tires specifically that are common between the cars. But all the components, like the core tub of the car, all the bodywork of the car, all that is uniquely developed by the teams. And then they will go and manufacture these components in-house. So the teams have varying numbers of employees from 500 to 1,000 people, and there’s a lot of engineers that basically design all these components.

And then all the components are made in-house. There’s some subcontracting out. But it’s mainly made in-house from custom machined components and custom hand laid-up bits. So it’s all very customized.

KATHLEEN DAVIS: So there is this governing body of Formula One called the FIA, which sets these requirements for cars to meet. And a couple of years ago, they introduced new weight requirements for these cars. And some teams had heavier cars who wanted to trim down some weight. So why did they turn to reducing the amount of paint? To me, that doesn’t seem like a natural place to start.

KYLE FORSTER: Yeah, well, it’s one of those things where you’re kind of in the sport trying to get a lot of incremental gains. And every gram that you save on the car is a benefit. Now, the slopes for different cars vary. But roughly, you could think of it as about 10 kilograms is worth around 3/10 of a second per lap. And if you strip, say, 500 grams off the car, it’s worth about 0.015 seconds, which doesn’t sound like much. But at the Qatar GP for qualifying, that would have been the difference between seventh and eighth in qualifying. So it does make a difference.

There’s a minimum weight limit. There has been a minimum weight limit for a long time now. But the minimum weight limit changes with each regulation set. When we moved to newer wheels and tires in 2022, that was when the wheels and tires got a lot bigger. The cars got heavier. So the minimum weight limit came up.

However, with any big rules change– that was a big rules change in 2022– there was a large increase in the mass of the cars inherently by the design nature, by having those bigger and heavier wheels and tires. And what that means is that some teams are struggling to get to the minimum weight.

Now, once you’re below the minimum weight, you’re all good. You can just add ballast to get to the minimum weight. And you put that ballast where you want it to be. But if you’re above the minimum weight, you’re actually just losing lap time with no benefit. So if you’re, say, two, three kilos over, you’re losing a lot of time. So if you’re overweight, you need to find any way you can to strip weight off. And with the paint, let’s say that on an F1 car that the paint weighs around about 1 and 1/2 kilos, if you can strip, say, 30% of the paint off the car, well, then you save that 500 grams we spoke about earlier.

KATHLEEN DAVIS: Have there been any recent developments in paint science when it comes to Formula One?

KYLE FORSTER: Yeah, so the coatings used on F1 cars are very specific lightweight coatings. Obviously, it’s not quite my speciality into the coatings themselves. But my understanding is that you can get a very thin coating that still achieves the color you want and is very low density so you get a lightweight coating. And a few years ago, I think around about 2016, 2017, teams started rolling out these matte paint finishes. So instead of running gloss, they were running matte.

And by using these finishes, they were reducing a lot the weight of the paint on the car. Some of the estimates being thrown around at the time was that this could be worth up to about 600 grams. Now, obviously, you can never be sure with the numbers that come out from F1. But if that is correct, then that’s a big weight saving just from changing the paint from gloss to matte.

KATHLEEN DAVIS: Yeah, I wouldn’t necessarily make that correlation. So one of the appeals for some F1 fans is how teams really have to work creatively to meet constantly changing requirements for these cars. When you were with Mercedes as an engineer, was that a frustrating part of your job? Was it an opportunity to get creative? How did you feel about these changing requirements?

KYLE FORSTER: Yeah, I think the change of regs is a super interesting thing for the engineers because it happened– the aerodynamic regs changed quite a lot in the time span I was at Mercedes. And it was usually to do with things like trying to help the cars behind follow. So they would do adjustments like they would say, you could have less bargeboard height. Or you have to have a different front wing with less curvature.

And basically what this does is that it completely throws your old design out the window. And then you have a new design, a new airflow all over the car. And you have to now come up with new concepts that work better with that. And every time they change the rules, what you develop before as a concept won’t necessarily work anymore. So it means you now have to come up with something from scratch.

So it’s quite exciting from that perspective in that you move out of this region of optimizing an existing design into creating fresh and new designs that can deal with the new flow features. So from that point, it’s interesting. It’s always a little bit nerve wracking from the point of view of when you’re in a team like Mercedes, where I think Mercedes won, what, seven, eight championships in a row.

You’re going on a winning streak. And then the rules change. And then you’re terrified that this rules change is going to result in your car being super slow. And it gives an opportunity for another team to come up. And while I was at Mercedes, we successfully defended across several rules changes. But it is a bit nerve wracking, thinking that you might have an issue where a rules change causes you to get a much slower car that could not win anymore.

KATHLEEN DAVIS: Right. I would imagine. Just a quick note– I’m Kathleen Davis, and this is Science Friday from WNYC Studios.

In case you’re just joining us, I’m talking to Kyle Forster about the aerodynamic science of Formula One. Are there future F1 engineering innovations that you’ve got your eye on that you’re really excited to see get implemented in the future?

KYLE FORSTER: Oh, that’s an interesting question because the thing with the innovations in F1 is that a lot of it is getting more and more controlled by the rules these days. Obviously, a lot of your audience is based in the USA and may be familiar with IndyCar. Now, IndyCar is a spec series, where basically all the cars are essentially the same car. There’s some slight differences, but fundamentally, the tub and the core design of the car is the same.

In F1, all the designs are completely different, like we discussed earlier. But the rules have been tightening year on year to try and bring a little bit more convergence to the cars. And that is hoped to make the racing better. And largely, that does seem to be the case because the field is drawing closer.

However, it does stifle a little bit some of the innovations that you’d expect to see. For example, in the sort of 2020 spec cars, we had all this really cool hydraulic suspension. But these days, you’re actually really limited. You’re not allowed to have hydraulic suspension anymore. You’re not allowed to have [INAUDIBLE], which are another suspension technology.

So from that perspective, you lose a lot of those cool developments. However, one of the things that I’m quite interested in is there’s a new set of powertrain rules coming out soon. And those rules should lead to some new and interesting powertrain solutions. And I think that what we see coming out in those next few years over the powertrain changes could be quite interesting.

KATHLEEN DAVIS: Mhm. So looking forward a bit, F1 still largely uses gasoline-powered engines. There has been a little bit of a move to hybrids. But these gas-powered engines are still king. Formula E is something that exists, which is a race for electric cars. But is there a tension between this nostalgic history in the sport for gas-powered engines and switching to something like electric motors?

KYLE FORSTER: Yeah, I think, in terms of the tension, a lot of the tension seems to be more within the fans than the engineers. As an engineer, I don’t specifically have a problem with it moving to more electric. I think the largest issue is the energy density issue, where, at the moment, these cars are so heavily dependent on weight for performance that, if you start to add mass by having poor energy density, the car will get a lot slower. So that issue needs to be solved, and that’s one of the holdups of electric powertrains is that they just don’t have the energy density.

So from an engineering perspective, you have to solve that. And then once that’s solved, once the energy density issue is solved, well, then I don’t see any issue with the moving to full electric once we get to that point. But I do know that there is a lot of tension when you go out on social media and have a look that a lot of fans are interested in the purity. And personally, I do love the noise of particularly the older generation F1 cars back when they were v10s and even the v8s. The sound of those when you’re next to them in real life is quite something. And that will be something that’ll be a bit sad to lose once we move to a more electric-based car.

KATHLEEN DAVIS: Well Kyle, thank you so much for taking the time to be with us today. I hope you have a good race week, and thank you for being with us.

KYLE FORSTER: No problem at all. Pleasure to be here.

KATHLEEN DAVIS: Dr. Kyle Forster, former aerodynamicist for the Mercedes AMG F1 team and a lead aerodynamicist for JKF Consultants.

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