The removal of the MGU-H from Formula 1's 2026 power units has turned race starts into one of the most technically treacherous moments ahead of the first race, and the paddock is bracing itself
Piastri got stuck on the grid during a practice start in Bahrain last week
Formula 1’s biggest regulatory overhaul in over a decade has arrived, and with it a problem that nobody fully appreciated until drivers climbed into the new cars for the first time: getting off the grid cleanly is now exponentially more difficult, more dangerous, and far less predictable than it has been for years.
What only last year was a split-second mix of revs, clutch control and traction has now become a prolonged, nerve-shredding ritual that has teams and drivers genuinely worried ahead of the season-opening Australian Grand Prix in Melbourne.
“Starts need to be addressed because, probably as we’ve all seen, it’s a pretty complicated process now to have a safe start, let alone a competitive one,” McLaren‘s Oscar Piastri said after the first Bahrain test last week.
In order to understand why starts have become so complicated, it’s important to first understand what has been lost.
The previous generation of power units – which served F1 from 2014 until the end of 2025 – featured the MGU-H (Motor Generator Unit-Heat).
This unit was attached to the turbocharger shaft and performed a critical dual function: it harvested excess energy from the exhaust gases spinning the turbine, and it could also act as an electric motor to pre-spin the turbo compressor, forcing it up to its effective operating speed almost instantaneously.
In the context of race starts, this was crucial.
Drivers sitting on the grid could have their turbocharger spooled up and ready to deliver maximum boost pressure in a matter of moments, at relatively modest engine speeds of between 9,000 and 10,000 rpm.
The MGU-H effectively eliminated turbo lag at the very moment drivers needed power delivery to be flawless.
Piastri has warned of chaos at the starts after the Bahrain test
Grand Prix Photo
The 2026 regulations have removed the MGU-H entirely from the power unit architecture, a decision driven largely by cost and complexity concerns.
In its place, the new hybrid system increases the role of the MGU-K (Motor Generator Unit-Kinetic), which now contributes close to 350 kilowatts – roughly 50 per cent of the total power output – during deployment.
That has been a huge shift in philosophy: in removing the MGU-H, the rules have removed the one component that had been quietly making race starts look effortless for over a decade.
Before this change, the success of a race start depended on reaction time and controlling the wheelspin.
It has meant that it was less likely to have disastrous starts unless there was a big mistake or some sort of technical glitch.
The new start physics
Without an electrical motor to pre-spin the turbocharger, the only means of spooling it up is the old-fashioned way: high exhaust gas flow from the internal combustion engine, which means high rpm.
Data from the Bahrain pre-season test recorded peaks of over 13,000 rpm during practice starts – values that the previous power units only reached during moments of maximum effort, certainly not while cars were at a standstill.
In past years, thanks to the MGU-H, the average start rpm fluctuated between 10,000 and 12,000 rpm. Today’s drivers must sit stationary on the grid, engine screaming, for an extended period – often 10 seconds or more – simply waiting for the turbo to reach an efficient operating speed and stabilise.
A viral video from the F1 test in Bahrain showed Lewis Hamilton practising Ferrari‘s start procedure, revving his engine for 20 seconds before he gets going.
2026 starts will look nothing like last year’s
Grand Prix Photo
However, the high revs alone are only half the battle. As the engine increases in rpm, it builds up exhaust gas flow but, because the engine is not under load, that is working against boost pressure. For everything to get to a certain rpm and stabilise takes time — and this is also dependent on the actual turbo size and the relationship between the turbine and compressor capacity.
But the difficulty doesn’t end there: if a driver releases the clutch at that rpm without perfect calibration, the result is excessive wheelspin. The window of success is now very narrow.
Compounding all of this is an explicit regulatory restriction introduced specifically for 2026.
Article 5.4.12 of the technical regulations states: “With the exception of cars starting or resuming the race from the pitlane, the MGU-K may only be used during a standing start once the car has reached 50km/h [31mph].”
This means that for the most critical phase of the start – the initial launch – drivers cannot lean on the MGU-K’s electric torque to make up for any deficiencies in turbo response. Any driver who has not balanced the revs, clutch release and turbo speed perfectly has no means of recovering until they are up to at least 50km/h.
That is where the energy management dilemma truly bites.
Even once the 50km/h threshold is crossed, drivers would be reluctant to use the MGU-K to compensate for a poor start, because that entails using up battery charge – thus compromising the rest of the lap.
The 2026 cars are energy-hungry. While burning through energy would be logical in helping fill in for turbo lag on the run to the first corner, it would be wasted if that meant being left with an empty battery that makes the car a sitting duck coming out of it.
Safety concerns
What elevates this from a mere sporting curiosity to a genuine safety concern is the disparity it creates across the grid, as Piastri warned after the first Bahrain test.
The current start procedure means that once the final car has rolled into its grid slot, the five red lights begin illuminating at one-second intervals, with the race typically getting underway within 10 seconds of the last car stopping.
Stella has urged the FIA to make changes before the first race
McLaren
For drivers at the back of the field, this interval doesn’t give them sufficient time to get their cars into the right envelope for the race start, meaning that while those in the front half of the field are hurtling towards Turn 1 after getting their engines to the right rev range, those towards the back face chaos.
The implications are very serious.
F1 cars accelerate at rates that can generate enormous speed differentials between surrounding cars in a fraction of a second.
A driver who has nailed the turbo spooling perfectly can launch very fast; a driver who misjudged their preparation by even half a second may barely move.
The shambolic practice start sequence at the end of Bahrain testing – in which Piastri did not get away at all from the front row while only half the cars behind him moved – served as a vivid illustration of what awaits when conditions are not perfectly controlled.
The anxiety in the paddock has been hard to miss.
McLaren boss Andrea Stella has been perhaps the most forthright voice, and he was unambiguous about his concerns.
“We are not talking about how fast you are in qualifying. We are not talking about what is your race pace. We are talking about safety on the grid,” Stella said. “There are some topics which are simply bigger than the competitive interest. And for me, having safety on the grid, which can be achieved with a simple adjustment, is just a no-brainer.”
Among the drivers, few have disguised their unease.
Lando Norris was candid about the new complexity: “It’s a lot more complicated. As soon as you start to use any battery to help in any situation, you’re just taking away a lot of battery to use for the rest of the lap. I can maybe have a better start, but you can also run out of battery by the time you get to Turn 1, in some places like Mexico, for example.”
Bortoleto labelled the start procedure a “mess”
Grand Prix Photo
Haas driver Oliver Bearman was equally forthcoming about the knife-edge nature of the procedure. “It’s a lot more complicated and a bit more inconsistent. Now we have to spend a lot longer doing the wait phase prior to doing the actual start and it’s really on a knife-edge to get it right. It’s really a matter of milliseconds – if you’re too late or too early by half a second, then it doesn’t work.”
Audi’s Gabriel Bortoleto offered perhaps the most candid assessment of all. “Oh man, it’s complicated. The 10-second thing, and then after five seconds I already lost the count – then engines revving up, gear in and out, and you need to release the clutch. It’s quite a mess. It was much easier last year.”
The stalled rule change
The most politically intriguing dimension of the story is that a fix was, in fact, proposed months ago – and blocked.
Last summer, a proposal to revise the start light sequence had been put forward by F1’s Sporting Advisory Committee to the F1 Commission.
As the 2026 season approaches, Formula 1 must find a way to resolve its compression ratio controversy – but every possible solution comes with a cost somebody isn’t willing to pay
By
Pablo Elizalde
However, the idea was blocked by Ferrari, which argued that the problems with turbo lag had been well known by teams during the design of their power units, and that any outfit which had made concept decisions that did not work with the start regulations as laid down should live with it.
The implication being that Ferrari had engineered its power unit with a smaller turbo that is less susceptible to lag, and that changing the rules now would effectively reward rivals who had made different – and, in Ferrari’s view, less prudent – design choices.
It is a defensible position from a purely competitive standpoint, and it speaks to the way in which the start problem is not merely technical but deeply entangled with each manufacturer’s strategic bets during the design process.
With the Australian Grand Prix fast approaching, attention has turned to what can practically be done before the first race of the season.
Two options appear to be on the table. The first is delaying the minimum time between when the final car forms up on the grid and the lights sequence begins.
A further proposal involves increasing the permitted ‘superclipping’ limit – where cars harvest energy while still at full throttle – from 250kW to the full 350kW capacity of the MGU-K, which would give drivers more energy in reserve without resorting to more dangerous techniques.
The F1 Commission is set to discuss the matter at its next meeting, and the FIA retains the authority to push through rule changes on safety grounds even without unanimous agreement from the teams.
Whether that fix arrives in time for Melbourne remains to be seen. If it does not, Pierre Gasly‘s recommendation may prove to be very good advice: “I advise you to be sitting with your TV on in Australia, because it could be one that everybody remembers.”
