“Speed, it seems to me, provides the one genuinely modern pleasure” – Aldous Huxley 1931.
In this article, I want to explore speed, specifically the speed of road-going vehicles. If Aldous Huxley was right, then we may be living in very pleasurable times. The 21st Century has witnessed significant growth in what we can achieve with production vehicles, with the limit for maximum speed moving significantly ahead.
Fig. 1 – The first road car to brake 300km/h, the Lambourghini Countach
At the end of the 20th century, the fastest production car was the McLaren F1, which was capable to 386.4km/h. While this was impressive, the 300km/h barrier had been first broken by the Lambourghini Countach (309km/h) in 1974, meaning that for the last 25 years of the 20th Century, “the fastest car” achieved a 75km/h increase. (Lambourghini claimed 300km/h at launch, although it wasn’t verified until the 5000QV variant was tested externally)
Early in the 21st Century, we’ve seen the 400km/h record tumble to the Bugatti Veyron, and the title for “the fastest car” has been keenly fought over. Bugatti, Koennigsegg, SSC and lately BYD have pushed the barrier to over 490km/h (>300mph) within 2 decades. We have seen high speed records move back and forth between a couple of dedicated vehicle manufacturers in the last years, and vehicles capable of over 500km/h are on the drawing boards of more than one OEM today. Since the heyday of the McLaren F1, we’ve added well over 100km/h to “the fastest car” in the first quarter of the 21st Century.
Braking records
Fig.2 – The Koenigsegg Jesko Absolut, the fastest car from 0-400-0km/h
So cars are getting faster, and the individual “fastest car” records are being held for less and less time by each vehicle, suggesting a surge in available performance and technology. But as these cars go quicker and quicker, what is happening to reign in that speed? Are we seeing an equally significant shift in braking performance to match this outright pace? One of the most demanding benchmarks is the 0-400-0 km/h test: accelerating to 400 km/h, then braking back to zero in as short a time as possible. This discipline demands not only colossal power in both directions, but also extraordinary stability and braking technology.
The current benchmark belongs to the Koenigsegg Jesko Absolut, which in 2025 completed 0-400-0 in just 25.21 seconds at Örebro Airfield, Sweden. This eclipsed the Rimac Nevera R, which set a blistering 25.79-second time in 2023 using all-electric propulsion, 390 mm Brembo carbon-ceramic discs, and regenerative braking. Before that, the Koenigsegg Regera held the crown with 28.81 seconds (2023), its hybrid twin-turbo V8 and direct-drive system harnessed alongside 410 mm front / 395 mm rear carbon-ceramic rotors. In 2017, the Bugatti Chiron had set a certified record of 41.96 seconds, relying on its colossal W16 engine and 420 mm front / 400 mm rear carbon-ceramics clamped by titanium calipers.
Fig. 3 – The Koenigsegg Regera
Earlier still, Koenigsegg established dominance: the Agera RS and Agera R demonstrated unmatched 0-300-0 and 0-400-0 performance in the early 2010s, with the Agera R first proving the viability of the test. By comparison, in the early 2000s, Bugatti’s Veyron 16.4 was celebrated for raw speed (431 km/h verified top speed), though its 0-400-0 time was never formally benchmarked—its 400 mm carbon-ceramic brakes were state-of-the-art then.
From the Veyron to the Jesko Absolut, each generation demonstrates the relentless arms race between propulsion and stopping power. In these machines, achieving 400 km/h is half the battle—mastering the return to zero is where true engineering brilliance is proven.
🏁 0-400-0 km/h Record Timeline (2000–2025)
2005 – Bugatti Veyron 16.4
Record: Top speed (407 km/h), no official 0-400-0 benchmark.
Brakes: Carbon-ceramic rotors, 400 mm front, 380 mm rear.
Significance: First road car to exceed 400 km/h; set the stage for future braking tests.
2011 – Koenigsegg Agera R
Record: First verified 0-300-0 km/h world record (21.19 s, Guinness certified).
Brakes: Carbon-ceramic discs (397 mm front, 380 mm rear).
Significance: Established Koenigsegg’s dominance in acceleration-braking benchmarks.
2017 – Bugatti Chiron
Record: First fully verified 0-400-0 km/h, 41.96 seconds.
Brakes: 420 mm carbon-ceramic front, 400 mm rear, titanium calipers.
Significance: Raised the bar for complete production-car performance testing.
2019–2023 – Koenigsegg Regera
Record: 28.81 seconds (0-400-0), obliterating Chiron’s time.
Brakes: 410 mm carbon-ceramic front, 395 mm rear, with hybrid regen assist.
Significance: Showed how hybrid technology could sharpen both acceleration and braking.
2023 – Rimac Nevera R (Electric)
Record: 25.79 seconds (0-400-0).
Brakes: 390 mm Brembo carbon-ceramic discs + regenerative braking.
Significance: First EV to claim the title; blended electric regen with huge carbon-ceramic stoppers.
2025 – Koenigsegg Jesko Absolut
Record: 25.21 seconds, current world record.
Brakes: 410 mm front / 395 mm rear carbon-ceramic rotors, advanced aero-stability during braking.
Significance: The fastest and most refined demonstration yet of road-car acceleration and stopping power.
Fig. 4 – The Rimac Nevera R, the fastest EV from 0-400-0km/h
Show Stoppers
So how do these increasingly fast cars achieve braking records? What’s the secret sauce that allows that allows the cars to cook up such prodigious velocity arrests? When considering kerb weights in the region of 1400kg to 2150kg, the kinetic energy to be dealt with ranges from 8.5MJ to 13.25MJ. And when you consider the fact that the current record holder needs over 16s to accelerate from 0-400km/h, and only an additional 8s to decelerate again, you get a feel for the intensity of the energy harnessing. So, braking power well in excess of 1MW.
Well, as we can see from the timeline, the brake discs used between the record braking cars are relatively similar, and certainly not the largest in the market today (Bentley, Lamborghini, Land Rover and Porsche all offer larger carbon brakes to their customers). So the wheel brakes alone aren’t enough deliver the final word in stopping power.
When it comes to stopping from very high speeds, the truth is that there are different stages in the braking manoeuvre, and optimising each requires different elements in the vehicle control.
In terms of brake torque, the key aspects include a low Time to Lock (but taking account vehicle pitch response), pressure modulation to maximise tyre slip utilisation, and thermal resistance of the foundation brake components. The brake torque must be capable to overcome the available tyre grip, and the brake modulation must ensure that peak tyre adhesion is maximised.
But brakes alone won’t be enough
Having engineered the braking systems for many fast and heavy cars, I can speak from experience on the importance of a holistic approach to deceleration when working at these physical extremes. Deceleration sources (or “speed sinks”, if you will) include rolling and aerodynamic resistances, and of course powertrain inertias and regenerative torque.
Aerodynamics plays a pivotal role in the ability of a vehicle to reach significant speed, but also is a powerful ally in sinking that same speed. Active aerodynamic elements offer the chance to dramatically increase braking performance and efficiency at high speed, and can contribute significant deceleration during the initial braking phase. Bugatti engineered their record-braking vehicles to take advantage of a significant Air Brake configuration, allowing the vehicles to develop up to 2g deceleration while maximising rear axle braking contribution.
Fig.5 -Air Brake configuration for high speed
Clever use of air to maximise braking performance doesn’t just mean spoilers, however. Channelling air towards the brake disc and calliper is a necessary means of improving their thermal capacity, therefore increasing the amount of energy the foundation brake can safely absorb. It is relatively common amoung performance vehicles to devout some frontal real estate to braking air flow, but the use of active elements to enhance stability, cooling, drag and vehicle pitch marks these “record brakers” out from the crowd.
Fig. 6 – Frontal area vents to deliver cooling flow to foundation brakes
For many of the worlds’ fastest road cars, their electric powertrain offers another chance to enhance braking performance – Regenerative Braking. As discussed previously, the job of stopping an EV is a shared task, and while Regenerative Braking is part of the mix, even significantly powerful electric motors only contribute a small minority of the power absorption required, especially at elevated speeds.
Having said that, state-of-the-art Regenerative Braking systems will provide up to 0.6g in ideal conditions, so of a similar magnitude to Air Brakes, if properly deployed. Typically, both aerodynamic and regenerative braking can be layered on top of the foundation brake, and can greatly increase the overall braking performance.
To fully utilise the potential of regenerative braking, the tyre grip budget has to be carefully managed. As we mentioned already, during extreme deceleration, the tyre should be continually slipping, so the full longitudinal potential can be exploited (here a refresher on the concept, thanks to Concorde development). In practice, this means careful management of the wheel torque – and in the case of a performance EV, meticulous synchronisation of regenerative and friction braking. Teasing the best blend from an installed system is a calibration task, but many design decisions can help to enable this (installed brake and regenerative balance, inverter efficiency, battery C-rates to mention a few).
Jamais Contente?
So, as we approach the era of the 500km/h road car, we can see that the technological race is only hotting up. And as cars get faster, the braking task becomes more holistic. The use of cutting edge foundation brakes together with a battery of neighbouring systems allows for megawatt deceleration events.
I look forward to the next years in hypercar performance. Innovation never stops, and good engineers are never satisfied.
