Porpoising in F1, explained
The 2022 ground-effect cars found a way to make downforce and discomfort arrive in the same violent rhythm, and it took a season of regulation to beat it out of them.
By Indy GillWatch the onboard from the Jeddah straight in early 2022 and you'll see something that looks like a mechanical fault: the front wing shuddering, the horizon jumping in the mirrors, the driver's helmet ricocheting against the headrest at 200mph. It wasn't broken. It was working exactly as the regulations intended, and that was the problem.
What porpoising actually is
Porpoising is the rapid, rhythmic bouncing that hit Formula 1's ground-effect cars when the 2022 technical rules returned downforce generation to the floor. As the car loads up with downforce it squats down on its suspension, and if the floor gets too close to the track surface the airflow underneath can stall. That sudden loss of downforce lets the car spring back up, which lets the airflow reattach, which floods the downforce straight back in and drags the car down again. Do that ten or fifteen times a second down a long straight and you get a car that appears to be swimming, hence the name: a porpoise breaking the surface, diving, breaking the surface again.
Why it mattered beyond the lap time
This wasn't just an ugly visual. Several drivers reported genuine back pain after races in 2022, Lewis Hamilton among the most vocal after struggling through Baku, and the concern quickly moved from comfort to safety. Engineers found themselves in the strange position of knowing their fastest setup was also their most physically punishing one. That's the tension that pulled the FIA in: a phenomenon born from pure aerodynamic efficiency that was also, credibly, a threat to driver welfare.
The physics of the bounce
The 2022 rules asked teams to generate downforce the way ground-effect cars did in the late 1970s, shaping the floor into venturi tunnels that accelerate air underneath the car and pull it toward the tarmac. The lower the floor sits, the faster that air moves and the more downforce it makes; it's a virtuous circle right up until it isn't. Push the ride height low enough and the gap between floor and track closes so tight the airflow can no longer stay attached. It separates, stalls, and the downforce holding the car down vanishes in an instant. The suspension springs the car back up, the gap reopens, the airflow reattaches, downforce floods back in, and the whole cycle restarts. Every team chasing lap time in 2022 was, by design, running as close to that cliff edge as they dared, which is exactly why so many of them fell off it.
Not every car suffered equally. Mercedes ran famously low and famously stiff in search of ground-effect gains other teams left on the table, and paid for it with the worst bouncing on the grid, while cars built with more suspension margin rode the phenomenon out with barely a shudder. That split told its own story about the trade-off at the heart of the regulations: run low and fast and risk the bounce, or run higher and smoother and give away lap time.
How the FIA stepped in mid-season
By round eight the complaints had become a governance problem, not just a technical curiosity, and the FIA moved to address the aerodynamic oscillations and the toll they were taking on drivers. The first fix was a monitoring regime rather than an outright ban on low ride heights: the FIA introduced an Aerodynamic Oscillation Metric, built around accelerometer data, to measure how violently a chassis was moving and to intervene against any car that crossed the threshold. That gave stewards a number to point to instead of relying on a driver's own description of how sore his back felt.
Alongside it came a crackdown on flexible floors. Teams had been quietly exploiting the give in the floor edge and skid plank to run effectively lower ride heights than the rules intended, without technically breaching the stated limits, so the FIA tightened the plank and skid stiffness rules from the Belgian Grand Prix onward, working alongside the new oscillation metric. The FIA was explicit that these were short-term measures, not the finished answer to the problem.
The permanent fix for 2023
The structural change arrived with the following year's technical regulations, targeting the geometry of the floor rather than just policing its behaviour. The outer edge of the floor ahead of the rear wheels had to be raised by fifteen millimetres, widening the gap the airflow has to cross before it stalls and buying teams a bigger margin between maximum downforce and a sudden loss of it. The FIA also tightened how much the floor could flex under load: where roughly eight millimetres of downward deflection and twelve upward had been tolerated in 2022, the 2023 rules cut the limit to five millimetres in both directions. A standardised accelerometer, mandated across the grid, gave the FIA a consistent read on oscillation frequency for every car rather than relying on each team's own telemetry.
The compromise wasn't painless, and it wasn't as severe as first proposed either. The FIA's original plan called for a much larger 25mm floor raise, but the final figure settled at fifteen, partly because most of the porpoising problem had already been engineered out by the teams themselves by the time the new rules landed. That detail is worth sitting with: the regulation locked in a safety margin and stopped anyone drifting back toward the cliff edge, more than it single-handedly cured a disease that was already in remission.
Where you still see it today
Full-blown porpoising, the kind that had cameramen zooming in on shuddering rear wings in 2022, is rare now on a well-sorted current-generation car. What survives is a milder cousin: a car skipping or bottoming out over a specific bump or kerb, particularly at a bumpy circuit or when a team has trimmed ride height for one low-drag qualifying lap. Listen for engineers warning a driver about the car touching down through a fast section, or watch a car's rear end shimmy fractionally on a long straight; that's the same stall-and-reattach cycle in miniature, just contained within tighter deflection limits than the sport used to allow. It shows up hardest at circuits with long, fast straights and aggressive kerbs in the same lap, where the demands on ride height pull in opposite directions.
For anyone chasing the wider story, this is really a chapter in how the floor and diffuser generate the bulk of a modern F1 car's downforce, and it sits close to why ride height and suspension setup are argued over so fiercely on the pit wall. It's also a clean case study in how technical regulations get rewritten mid-season when safety, not just performance, forces the FIA's hand.
The lesson for the next generation of rules is already visible in how closely the next set of cars will be watched for the same symptom the moment they hit the track. Ground effect and low ride heights aren't going away, so every time F1 tweaks the floor rules again, the first question in the garage will be the one that dogged 2022: how close to the stall point can we run before the car starts talking back?