F1's energy recovery system now runs on a single motor generator unit producing 350 kilowatts, up from 120. The second unit, the MGU-H, has been deleted entirely, despite being the more ingenious of the two.
That is not an engineering failure. It is one of the more interesting trade-offs the sport has ever made, and it is the reason Audi is on the grid.
What is ERS in F1?
ERS stands for Energy Recovery System. It is the hybrid half of a Formula 1 power unit: it captures energy that would otherwise be thrown away as heat, stores it in a battery, and hands it back to the driver as extra power.
Until 2026 it did this two ways.
The MGU-K, K for kinetic, harvests under braking. A car decelerating from 320 km/h is shedding an enormous amount of kinetic energy, and in an ordinary car all of it becomes heat in the brake discs. The MGU-K intercepts some of it and turns it into electricity.
The MGU-H, H for heat, was the clever one. It sat on the turbocharger shaft and harvested energy from exhaust gas that had already done its job driving the turbo. Waste heat, going out of the back of the car, converted into charge.
Why was the MGU-H so good, and why is it gone?
The MGU-H was extraordinarily effective. It captured up to 70% of the total energy recovered per lap. Most of the electricity in a modern F1 car was coming from exhaust heat rather than from braking.
It also solved turbo lag almost completely, because the same unit could spin the turbo up electrically before the exhaust gas arrived.
The problem was everything else about it.
The MGU-H spun at up to 125,000 rpm. Building something that survives that, attached to an exhaust, at F1 temperatures, for a full season, is brutally difficult. It was unreliable, and it was hideously expensive to develop.
That expense became a political problem rather than only a technical one. The MGU-H was the single biggest barrier to a new manufacturer entering Formula 1. Any newcomer faced years and hundreds of millions catching up on a component nobody uses anywhere else in the world.
So the sport made a straight trade: give up the cleverest part of the power unit, and get new manufacturers in return. Audi's entry is the direct consequence.
What the 2026 ERS actually does
With the MGU-H gone, everything is loaded onto a much bigger MGU-K.
Output: 350 kW, up from the 120 kW it produced from 2014 through 2025. Nearly triple.
Recovery: up to 9 MJ per lap into the battery, roughly double the old capacity.
Deployment: bursts of up to 4 MJ, and crucially the system can use as many of those bursts per lap as the battery can supply, rather than being limited to one.
Meanwhile the internal combustion engine has been wound back deliberately, from roughly 550 to 600 kW down to about 400 kW.
Put those together and you get the headline: a 2026 F1 power unit is roughly half combustion, half electric. That is a genuine philosophical change, not a tweak.
What that changes about how a car is driven
Three things follow, and they are already visible.
Recovery matters more than it ever has. Without exhaust harvesting, every joule in the battery has to come from braking. That makes braking zones an energy opportunity as well as a lap-time one, and it makes circuits with few braking events, like Spa and Monza, genuinely awkward to charge at.
Deployment becomes a strategic choice within the lap. Multiple 4 MJ bursts rather than one continuous trickle means drivers and engineers decide where the electrical power goes. Which straight, which exit, defending or attacking.
Energy management is now a visible part of racing. When a driver says they are "out of battery" at the end of a straight, that is not a figure of speech. It is a car that has spent its deployment and is running on 400 kW of combustion while the car behind still has charge.
Why the numbers sound smaller than they are
A reasonable objection: if the engine lost 150 kW and the hybrid gained 230 kW, why are the cars not dramatically faster?
Because power is only one input. The 2026 regulations arrived alongside changes to aerodynamics and car dimensions, and the sport was not aiming for a lap-time jump. It was aiming for closer racing, cheaper entry and a power unit that manufacturers actually want to build.
Judging the 2026 rules on top speed alone misses what they were designed to do.
ERS in one paragraph
Energy that would be wasted gets captured, stored and reused. Before 2026, F1 captured it from braking and from exhaust heat, and the heat side did most of the work. From 2026, F1 captures it from braking only, using a much larger motor, and splits the car's power roughly evenly between petrol and electricity. The sport gave up its most sophisticated component to make the sport easier to enter.
Watching it happen
Deployment, recovery and battery state are part of the live data stream during a session, alongside the timing that shows what it produces.
Our app puts every car on the circuit map during a session with a timing tower carrying gaps, intervals, tyre compound and tyre age, pit stop counts and positions gained or lost. Driver radio streams live with the transcript beside the audio, which is where energy management conversations actually happen: engineers telling drivers where to lift, where to deploy, and when they have nothing left.
It also collects every FIA document published across the weekend, including the power unit element allocations that make grid penalties inevitable before anyone announces them. We wrote a guide to what the FIA publishes and how to read it.
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