Kimi Antonelli: Why is Mercedes driver taking grid penalties at Italian Grand Prix in Monza on home soil?

Antonelli will start at the back of the grid as he will exceed the limit of four power units that can be used in a season before incurring grid penalties.

It means the Mercedes driver could see his 59-point lead over team-mate George Russell and Ferrari's Lewis Hamilton cut significantly, while a third consecutive win for McLaren's Lando Norris could enable the reigning world champion to make major inroads into his 83-point deficit to Antonelli.

With Mercedes having confirmed that Antonelli is taking a grid penalty for changing his engine at this weekend's Italian Grand Prix, Sky Sports F1 explain why the world championship leader has opted to do so at his home race.

Why does Antonelli need to take a penalty?

Mercedes have generally had the car to beat for most of this year, particularly earlier in the season, but the W17 has suffered from reliability issues.

In Antonelli's case, he suffered an electrical shutdown when running in second at the Barcelona-Catalunya Grand Prix in June, which damaged one engine.

Then Mercedes discovered an issue with his engine after July's British Grand Prix, which led the team to fit Antonelli with a fourth engine at the Belgian Grand Prix three races ago, meaning he was already on the limit of the number of power units that can be used before suffering from grid penalties.

F1 power units are split into different components. Had Mercedes only changed the internal combustion engine, which would be Antonelli's fifth of the season, the Italian would only have a 10-grid place penalty.

But Mercedes boss Toto Wolff says Antonelli will "take the full thing", meaning they will change other components that will take him above their respective limits, including the energy store and control electronics. They will both be worth five-grid places each, thus taking Antonelli to 20 grid places.

Once a driver has a 15-grid place penalty or more, the FIA automatically puts you at "the back of the grid", which will happen to Antonelli in Monza.

Monza is known for its long straights, so overtaking is relatively easy compared to other upcoming tracks such as Madrid and Baku, which are street circuits.

At the 2021 Italian Grand Prix, Valtteri Bottas powered through from the back to the podium after an engine change, while Max Verstappen won from 14th at the 2022 Belgian Grand Prix.

"Monza is an energy-starved circuit with four overtaking zones. A driver cannot defend all of them, so a faster car should be able to make progress relatively straightforwardly," said Mercedes trackside engineering director Andrew Shovlin on the team's Nu Silver Arrows Radio Show .

"The primary factor is when the hardware is needed. We have lost internal combustion engines at relatively low mileage, so we know we must introduce new components by a certain point. If that falls at a circuit where starting at the back would be particularly costly, we may choose to bring the change forward."

Currently, 12 more rounds remain of the 2026 F1 season - although that could be reduced to 11 depending on whether the Qatar and Abu Dhabi Grands Prix take place.

Shovlin also hinted Mercedes would rather take grid penalties with Antonelli now, compared to later in the year when the title race could be closer.

"We also lead both championships, so there is logic in taking the pain now rather than adding pressure if the margins tighten later in the season," he continued.

Russell is in a similar position to Antonelli and will also have grid penalties for exceeding his engine allocation later this season.

Sky Sports News understand that Russell will definitely not join Antonelli at the back of the grid this weekend, as Mercedes continue to assess the British driver's situation.

"We must manage the remaining events so that both cars reach the end of the season with the freshest and best-performing hardware possible," said deputy team principal Bradley Lord.

"It is a constant trade-off between the risk of running high-mileage components and the points cost of taking a grid penalty and recovering through the field."

Thursday September 3 1pm: Drivers' Press Conference 4pm: Paddock Uncut

Friday September 4 7.30am: F3 Practice 8.55am: F2 Practice 11am: Italian Grand Prix Practice One (session starts at 11.30pm)* 12.55pm: F3 Qualifying 1.50pm: F2 Qualifying 2.35pm: Italian Grand Prix Practice Two (session starts at 3pm) 4.15pm: The F1 Show 5.20pm: Team Bosses' Press Conference

Saturday September 5 8.25am: F3 Sprint 11.15am: Italian Grand Prix Practice Three (session starts at 11:30am) 1.10pm: F2 Sprint 2.15pm: Italian Grand Prix Qualifying build-up 3pm: ITALIAN GRAND PRIX QUALIFYING* 5pm: Ted's Qualifying Notebook

Sunday September 6 7.10am: F3 Feature Race 8.40am: F2 Feature Race 10.40am: Porsche Supercup Race 12.30pm: Grand Prix Sunday: Italian GP build-up 2pm: THE ITALIAN GRAND PRIX 4pm: Chequered Flag: Italian GP reaction 5pm: Ted's Notebook

Formula 1 heads to Monza for Ferrari's home race at the Italian Grand Prix this weekend, live on Sky Sports F1. Stream Sky Sports with NOW - no contract, cancel anytime