SlipStream Saturdays: F1’s Curious 2026 Power Units & Where We Stand After Five Races

Early in the season, I promised to write a piece explaining how the all-new 2026 power units work. I’ll be brutally honest: I still don’t have a firm grip on everything happening over, say, one race lap. But promises are promises, so in a fit of what can only be described as masochistic, I’ll try to explain everything I know.

First, I’ll cover (in very simple terms) how the moving pieces fit together. Then, I’ll explain some changes happening this year, and the potential changes for 2027 that could play a central role in whether or not the sport’s current top driver, Max Verstappen, decides to walk.

The 2026 Power Units – A Guide For Mere Mortals

Let’s begin with how motor racing traditionally works. Driver pushes right pedal: car goes faster. Driver pushes left pedal: car slows down. Driver turns wheel: car goes in a different direction. The very last bit hasn’t changed but the first two have changed, and that’s why Verstappen – along with many others – believe it’s no longer “pure racing.”

The spanner in the works is not only due to the electrical power, as F1 engines have been using electrical energy in some form for well over 10 years now, but it’s also down to the fact that the electrical energy contributes roughly 50% of the engine’s performance.

The other 50% is from the internal combustion engine (ICE). That’s the noisy bit we all know and love, and it does what it’s always done: it burns fuel (now 100% renewable) to drive the wheels.

So, why is the electrical bit causing so many problems? Simple: the batteries don’t have enough energy, which has created some less-than-ideal consequences. To sum it up, many say that the 2026 cars are “energy starved,” so I’ll explain exactly why and what that means.

F1 Super-Clipping & Battery Power Explained

The batteries in these cars are only about 2% the size of one you’d find in an average road-going EV. That means it can only deliver power for around 20 seconds each lap. On a track like Spa-Francorchamps, which is full-throttle for 70-75 seconds, you don’t need to be a math professor to understand the problem.

There are a few modes to deploy your electrical power, and the regulations also state exactly how much power you’re allowed to get. There’s a normal deployment mode – you hit the accelerator, and you get power from the ICE and from the battery.

One thing to understand is that the electrical power is like an on-off switch. There’s no squeezing the pedal to manage how much energy you get. It’s all or nothing. Oscar Piastri (in Melbourne) and Max Verstappen (in Miami) both fell victim to this massive surge.

Then there’s “Boost” and “Overtake” mode. The “Boost” mode gives the driver a button to manually override the system and get an extra bit of juice (if the battery has enough charge).

The “Overtake” mode gives you an even bigger shot of electrical power, but it only gets activated when your car is within 1 second of the car in front (the same as the old Drag Reduction System).

The problem with the whole boost and overtake modes is the size of the batteries. If you use either mode, your battery will run out sooner, and the car you just passed could sail on by a few corners later. This is why Fernando Alonso wryly referred to F1 2026 as the “battery championship.” It has been very entertaining to watch for many fans, but the drivers hate it because it’s become a game of who has the most battery power.

How Do F1 Engines Generate Electrical Power?

Given that the batteries have such limited energy, they need frequent recharging, also called “harvesting.” This has led to a situation where drivers are scrambling to get some extra charging done wherever and whenever possible.

Still with me? Great, I think I’m still with me, too (just). The really confusing part is how and when that recharging/harvesting happens. The first type of charging is regenerative, which happens during braking, or when a driver’s foot is off the go-fast pedal (this is known as lift-and-coast).

The problem is that drivers are now going much slower than normal through some corners to gain some extra recharging. So, instead of driving as fast as humanly and physically possible, like F1 cars should be doing, they’re now pootling around some parts of the track. For someone like Max Verstappen, it’s both counterintuitive and a little ridiculous (hence his threats to walk).

The second type of charging is called “super clipping.” This is where the right pedal is pushed firmly to the floor, but the generator is also in recharge mode. In effect, the generator is working against the combustion engine, which is why you hear the note of the engine dropping towards the end of long straights. This is another reason that many drivers and fans say “it’s not F1.” For purists, an F1 engine should be screaming its lungs out until the driver stomps on the brakes!

Finally, it’s worth noting that there were limits on how much energy the generators were allowed to generate at any given moment. This is one area that has come under review. If you allow the generators to create more energy when they’re running, you won’t need to use them so much.

F1 Engine Management In 2026 – It Gets Even More Technical

I’m not going to dwell on this too much, because the teams aren’t in a hurry to explain their secrets. But the drivers aren’t fully in control of how the batteries are being charged or deployed.

The teams have developed complex computer algorithms that work out the best places to charge and deploy electrical energy across a lap. As far as I can tell, this is based on what has happened in previous laps.

For Charles Leclerc in China, this created an issue when he had a small slide out of one corner during qualifying. The computer got confused about where was fast and where was slow, because there was an unexpected drop in speed through one corner. That then messed up Charles’ next lap, because the computer algorithm decided on a less-than-optimal solution.

F1’s Temporary Engine Fixes In 2026 (So Far)

As of the 2026 Miami Grand Prix, the FIA implemented several band-aid solutions to address some of the problems highlighted above:

• The amount of recharging power allowed during super-clipping was increased. Think of it like a 15W charger vs a 25W charger for your phone. The intention was to reduce how much time cars spent super-clipping, as well as to reduce the need to go really slowly through corners
• The amount of “boost” power was reduced, so the battery can actually last a bit longer on each lap
• Battery recharging during qualifying was slightly reduced, so drivers would be forced to drive at full-tilt during the whole lap

Proposed F1 Engine Fixes for 2027 – A New Raft of Problems

One solution would be to increase the size of the batteries, but batteries come with a lot of weight, which is something F1 is trying to avoid (lighter, more nimble cars were a key goal in these new regulations).

Another possibility is to have regenerative charging on both the front and rear axles, as it currently only works through the rear. This would give the batteries almost double the recharging potential.

The idea was floated several years ago, when the regulations were first being developed, but it was vetoed by Mercedes/Toto Wolff (because Audi has a lot of experience with this arrangement). Doing it now would require a major redesign of the power units, and it’s not clear whether Toto Wolff would even agree.

So, if you can’t increase the battery power or the recharging set-up, you bump the amount of power from the Internal Combustion Engine (ICE). That’s exactly what’s now being discussed.

The current proposal is to increase the amount of fuel entering the ICE, which would increase its power without requiring a ground-up redesign. The goal is to make it a 60/40 split between ICE and electrical energy.

It’s worth noting that Christian Horner suggested a 60/40 split over three years ago and was met with mockery from his longtime nemesis, Toto Wolff (there’s a pattern here). Ironically, Wolff is now fully in favor of the change. Sigh.

Anyway, I digress. While a change to 60/40 sounds nice and simple, this is F1, and things are never nice and simple. Increasing the fuel flow means the engines will need bigger fuel tanks to cover a full race distance. The problem here is the budget cap. Some teams were planning to use their 2026 chassis in 2027 to save money. As a result, they don’t want to redesign their chassis around new, larger fuel tanks.

To get around this, there’s talk about keeping the same fuel tanks, but limiting each car to just one pre-race lap to the grid – traditionally, they’ve done as many as they want. Some longer races might also be reduced by a few laps, which is likely to upset media sponsors (“we paid for 50 laps, not 48”).

None of this is set in stone yet. Mercedes and Red Bull are happy with the proposed changes, while Honda is on the fence.

Audi is complaining that the required changes will cost ~$10 million, which they haven’t budgeted for. It’s likely they’re still getting to grips with their current design, and don’t want the added trouble.

And, finally, Ferrari is dragging its feet because it might lose an advantage it hopes to get from ADUO (which I’ll explain next). Ferrari’s customer teams (like Cadillac and Haas) are following whatever Ferrari says.

Enter ADUO – Huh?

Ok, so I’ve covered the actual engines, how they work (kind of), and what’s being discussed in an effort to make them better next year. However, there are a few other things making headlines about the 2026 engines.

The first is ADUO – Additional Development and Upgrade Opportunities. This rule is all about the internal combustion engine (ICE), and it was created to help struggling teams catch up.

In the past, engine development was frozen to stop a spending war. For engine manufacturers who were down on power, like Renault, that meant they could never close the gap. That’s what ADUO is meant to solve.

For 2026, the FIA will check relative ICE performance three times, and then give extra upgrade opportunities to those who are behind. The first cut-off was Canada, which means we’ll learn who can upgrade their engine around the time of the Monaco GP. The next two cut-offs are Hungary (Round 11) and Mexico (Round 18).

Who Will Benefit From ADUO After Monaco?

As with all things F1, there’s a lot of political maneuvering going on. Most agree that Mercedes has the best engine, and Ferrari has been telling anyone who will listen that they’re more than 2% behind Mercedes (which is what is needed to be allowed an upgrade).

Honda is clearly struggling, so they’ll almost certainly get an upgrade, possibly two (to be given two upgrades, an engine has to be more than 4% behind).

Red Bull is intriguing. Some voices in the F1 paddock believe that Red Bull’s very first F1 engine is on a par with Mercedes, which would be an impressive feat. The team hasn’t been making nearly as much noise as Ferrari about getting an upgrade, which would suggest they are, indeed, pretty close to Mercedes’ benchmark.

Audi is the final engine manufacturer, and it’s unknown how their performance stacks up. Their power unit has been decent, so it’s unclear if their race results have been down to the engine or the chassis (or, a combination of both).

One Final Wrinkle For 2026 – The Engine Compression Ratio Battle

One final point is a loophole that Mercedes – and possibly Red Bull – are believed to have exploited in the new regulations.

This focuses on the engine’s compression ratio, which is how tightly the air is compressed in the engine’s cylinder. The regulations called for a ratio of 16:1, which was to be measured at normal (ambient) air temperature.

Mercedes is believed to have found a way to achieve a 18:1 ratio at operating temperature – once the engine has warmed up on track – which would give them more power in actual race conditions. Ferrari, Audi, and Honda weren’t happy!

As a result of some very vocal protests, the FIA introduced a new ruling at the start of the year. As of Monaco, they will also test the compression ratio at operating temperature, to make sure it’s still the required 16:1. Monaco will be the first time we see if it’s had any effect on Mercedes’ performance, but we might need to wait until the following race (Barcelona) to get a real read on it.

The Evolving F1 Engine Saga – What’s Worth Watching For The Rest of 2026?

Still with me? Give yourself a medal and a bottle of Champagne (disclaimer: Frontstretch is not funding post-article award ceremonies for determined readers).

From all the above, there are three key things to keep an eye on:

• What will be decided for 2027? Will the 60/40 split get through? If not, will Max Verstappen take his bat and ball and go elsewhere?
• Who will be allowed an ADUO upgrade? If Ferrari gets through, will they close the gap to Mercedes?
• Will the “compression ratio crackdown” have any impact on Mercedes after Monaco?

Yes, it all gets very complicated, but the technical battle between manufacturers is what I love about Formula 1. It’s great seeing the world’s top drivers battle on track. For me, it’s just as interesting seeing some of the brightest engineering minds battle off-track!