Fernando Alonso made an infamous comment whilst driving his Honda-powered McLaren at the 2015 Japanese Grand Prix. Having been overtaken by Marcus Ericsson in his backmarker Sauber, Alonso complained over team radio: “I’m caught on the straight like a GP2. This is embarrassing, very embarrassing… GP2 engine, GP2! Aaaaargh!”
It was embarrassing for Honda too at their home Grand Prix in their first year back in F1 as an engine manufacturer. Now GP2 has morphed into F2, and Fernando believes the much-hated 2026 F1 power units will perform worse at the upcoming Belgian Grand Prix than the current F2 engines.
The Warning Signs From Silverstone and Canada
From Miami to the Austrian Grand Prix, there was less talk about the lack of energy the latest iteration of F1 cars have, given the circuit configurations allowed for plenty of battery recharging. Yet come the British Grand Prix with its few large braking zones, the issues emerged once again.
Lewis Hamilton, whilst leading the Sprint in Silverstone, saw his energy-depleted Ferrari blown away by Kimi Antonelli along the straight. Something similar happened to him during the race—this time it was George Russell who sailed by as though he was standing still along the Hangar Straight.
The upcoming Spa circuit has even longer sections where the drivers do not brake at all, including from Turn 1 all the way to Turn 5 at the end of the Kemmel Straight. Then, as the cars reach the bottom of the hill, they are flat out from Turn 14 through to the final chicane before the start-finish line.
At the Canadian Grand Prix, the back straight is way shorter than the two sections outlined at Spa, and yet the cars were visibly slowing long before the braking zone into the final chicane. Both at the Belgian Grand Prix and later in Monza, these 2026 cars and power units will be exposed for the flawed concepts they truly are.
Simulator Realities: Sector 2 Without Power
“Silverstone and Spa, they are very thirsty on energy, and you cannot deploy [the battery] in all the straights,” said Alonso. “It’s going to be the same thing. If you deploy at Spa from Turn 1 to 5, finito for the rest of the lap.”
Having driven the track on the state-of-the-art Aston Martin simulator back in Silverstone, Fernando suggests the cars may be forced to run for longer than a minute without being able to deploy their battery power, which delivers up to 50% of the 2026 cars’ performance.
He warns further that given the internal combustion engine, which alone provides the power when the battery is depleted, has less horsepower than an F2 engine because it was designed to act together with the hybrid systems—not become the standalone source of power for the cars.
“You need to save a little bit there to have deployment from [Turn] 14 to the Bus Stop. But, if you deploy on those two straights, which is the optimal deployment, then there is a one-minute Sector 2 with no deployment at all.
“And with no deployment at all, we cannot forget that this year we have significantly less power than last year, and less power than F2. That’s the case when you cut the [battery] deployment. So, it’s a challenge.”
Cracking the Numbers: F2 vs. The 2026 F1 Engine
So, is Alonso’s claim that the F1 cars will be slower from the end of the Kemmel Straight through to Turn 14 justified? The F2 series has been using a Mecachrome V634 internal combustion engine since 2018, which produces 620 bhp and redlines at a maximum of 8,750 rpm from a 3.4-litre displacement together with a turbocharger.
Formula 1’s power units are built to split the power output 50/50 between the internal combustion engine and the hybrid battery system. Once the battery is fully depleted, the F1 cars run on just their ICE, which is capped at 400 kW—in the region of 535 bhp.
The F1 ICE output is capped by the amount of fuel flow the FIA has allowed it to receive, and as part of their green agenda, this was cut from 100 kg/h to 75 kg/h. This will be upped for the 2028 season, but for now, it’s not possible to turn up the fuel flow to compensate for a lack of electrical energy, given the fuel tanks are designed to carry only enough petrol to complete one Grand Prix distance.
Further, when the battery is depleted, part of the power of the ICE is used to generate electricity—this is called “super clipping”—so the full 535 bhp is not driving the car forward. Prima facie, this would appear to support Alonso’s comments, yet a deeper dive is required to complete the comparison.
Space-Age Efficiency vs. Traditional Muscle
F1 ICEs are a mere 1.6 litres in terms of their displacement, but the technology used to produce this unit is space-age by comparison to the heavy, traditional block used in F2. The modern F1 engine is a marvel of mechanical engineering, achieving a staggering 50% thermal efficiency. By comparison, the simpler, heavier F2 engine runs in the region of 25% thermal efficiency.
So the focus is on extracting every drop of energy through ultra-lean, rapid, and controlled combustion for F1. The absolute “secret sauce” of modern F1 engines is Turbulent Jet Ignition (TJI), a technology pioneered in F1 by Mahle and Ferrari in 2015, and then quickly adopted by every manufacturer.
In a normal car engine and in the F2 units, a spark plug ignites the fuel-air mixture in the centre of the cylinder, and a flame front expands outward like a ripple in a pond. If you try to run an engine “lean” (way more air than fuel to save fuel), a standard spark plug can’t ignite it reliably. The flame burns too slowly, or the fuel at the edges pocket-detonates, causing catastrophic engine knock (pre-ignition).
The TJI Factor and Optimised Torque
TJI completely fixes this by fundamentally changing how the fuel is lit: The component providing the spark sits in what is called a pre-chamber, and the fuel mix fed to the spark is relatively rich. An injector sprays fuel into the main chamber at a very lean rate of mix. Because the spark fires in the pre-chamber with a rich mix of fuel compared to air, the explosion is violent, and this high-pressure force created forces superheated, chemically active turbulent jets of flame out through the microscopic holes and radially into the main cylinder.
So instead of one single flame creating a ripple effect, multiple flame torches instantly blanket the large combustion chamber with the leaner mix of fuel. Furthermore, because the F1 ICE is paired with a highly sophisticated turbocharger and advanced packaging, it would still boast a significantly more optimised torque curve than the heavier, lower-tech Mecachrome unit found in F2.
Yet the raw bhp numbers still suggest Alonso may well be right. There will be much interest in the timing screens for Sector 2 when F2 takes to the track for qualifying on Friday.
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No more energy-starved than in Albert Park, Suzuka, or Silverstone, & barely any clipping even occurred towards the final chicane in Montreal.
Lap times will definitely still be faster than in F2.
Maybe HIS energy starved F1 car… doubt that all will 🤣