Why McLaren’s cars couldn’t race in China – and what it means for its F1 title defense

McLaren could not have experienced a worse start to the season. As the lights went out at the Chinese Grand Prix on Sunday, there were two empty spaces on the grid and their two drivers still in the garage. A double Did Not Start for last year’s championship-winning team, zero points, and a disaster of a weekend to follow a woeful opening race in Australia.

Two separate electrical problems with the engines were the reasons given by team principal Andrea Stella for Lando Norris and Oscar Piastri being unable to compete in Sunday’s race.

First, the issue was with Norris’ car. In the hours leading up to the race, the team worked on the world champion’s car. But when the Briton failed to turn up on the grid for the race start, the world learned of McLaren’s troubles. TV cameras focused on the team’s garage as speculation grew more intense with each passing minute.

Piastri, at least, had made it onto the grid. But then came another problem, leaving the Australian needing to be pushed back to the pits before the start.

“A disappointing day, quite frustrating, because we go racing to be on track,” Stella told reporters.

But what were McLaren’s issues, and why has there been an uptick in unreliability this season for several teams? How can millions of dollars be spent on a car only for it to be able to start a race? After all, four cars did not start Sunday’s race.

Why it happened

At McLaren, as it prepared Norris’ car ahead of the main China race, the team discovered it could not start the engine.

The fault was quickly traced to the hybrid system on the Mercedes engine, which, in 2026, as with all other engines, must consist of an internal combustion engine part, a turbocharger, a battery, a control electronics system and a Motor-Generator Unit Kinetic system that converts braking energy into electricity to add more engine power overall.

The issue of concern for McLaren was the battery on Norris’ engine. “We couldn’t communicate with this component,” Stella said.

As replacing the battery would take too long, McLaren tried to address the problem by replacing the Electronic Control Unit on Norris’ car, hoping that a new set of sensors would enable the battery to work with McLaren’s computers.

The ECU is a standard part that teams can replace in just a few minutes and is supplied by Motion Applied, a company that manages the software all F1 cars use. Motion Applied is a separate company from the McLaren race team and became independent of the McLaren Group in 2021. All 11 teams receive this part for each car under a tender agreement arranged by the FIA, motorsport’s governing body.

McLaren faces a big deficit in the constructors’ championship (Jade Gao / AFP via Getty Images)

Engine system issues can also sometimes be addressed by changing the steering wheel, since this part lets a driver control the complex software systems each car uses, as occurred in Russell’s qualifying drama last Saturday.

“We reprogrammed (the car), but there was no way to fix the problem,” said Stella. “Lando’s car was simply just not in condition to leave the garage.”

Then, when McLaren went to start Piastri’s car on the grid after the pre-race ceremonies, a similar but unrelated issue with his engine electrics was detected. “The car wouldn’t fire up again,” said Stella. “In a similar manner to Lando’s car, but actually on Oscar’s side it was easier to diagnose the problem.”

Stella did not specify which part of the electric system on Piastri’s car was not working as expected. Although it could work out what had gone wrong, McLaren did not have enough time to get its one driver who had reached the grid into the race.

Stella added: “It’s quite exceptional and uncharacteristic that you have two terminal problems pretty much at the same time, on the same component, which in this case is on the electrical side of the power unit.”

Until the root cause is confirmed, it remains unclear whether the fault lies with Mercedes hardware or McLaren’s integration of it.

McLaren and Mercedes’ High Performance Powertrains engine-building division will review the problem parts together ahead of the Japanese GP in two weeks. This is after Stella said, “these issues are understood in terms of what the problem is, but they are not fully understood in terms of the root cause.”

McLaren could arrive in Japan without knowing with certainty why either car failed to start. McLaren insists that problems did not occur within the few engine systems it builds itself.

The bigger picture

After it beat its engine supplier Mercedes to the constructors’ title in the last two seasons, McLaren has started 2026 adrift of the Silver Arrows, the sport’s current leading team. Following major changes to car design regulations for the 2026 campaign, Ferrari has also replaced Red Bull as the second-quickest team.

In such major rule resets, particularly when the FIA introduces new engine rules, as it has this year, reliability problems usually follow. This occurred in 2014, the last time teams were getting up to speed with new engines.

To further illustrate this, the new constructor Audi has had a DNS in each of the first two races. It lost the telemetry feed from Nico Hülkenberg’s car ahead of the start in Australia and suffered a so-far-unspecified issue that prevented Gabriel Bortoleto from starting in China.

Elsewhere, Aston Martin’s new era Honda engines have been an embarrassing shambles to this point, with a severe vibration issue that damages their batteries and leaves drivers unable to complete full race distances safely.

While the new Mercedes engine has proved class-leading through the opening two races of the season, securing a 1-2 in Australia and China with George Russell (winner in Australia) and Kimi Antonelli (winner in China), it has been unreliable.

In preseason testing, the works Mercedes team had several stoppages after introducing its race-specification 2026 engine on track during the third of three preseason tests, before the five engine builders (Mercedes, Ferrari, Red Bull, Audi and Honda) froze their engine development on March 1.

Mercedes had used an earlier engine specification in the first two tests, with its customer teams (McLaren, Williams and Alpine) only running the latest spec from the Australian season opener. Neither Williams nor Alpine reported any comparable electrical issues across the opening two races.

In China, a battery issue at the works team heavily disrupted Russell’s final session in main race qualifying, where Antonelli qualified ahead after the Briton had led the way in Shanghai to that point.

The battery problem caused Russell to stop on track briefly and it worsened when he restarted his car, leading to a gear selection issue that Mercedes could only rectify once he returned to the pits.

What does it mean for the title?

Whatever the root cause, McLaren is already 80 points behind Mercedes in the standings after two of 2026’s 22 races, and Norris is 36 points adrift of standings leader Russell. Piastri’s gap is even bigger at 48, after he scored his first points of 2026 with sixth in the Shanghai sprint. Those 19 laps are his only racing laps so far this season.

Stella said he and his drivers had watched the Chinese GP on TV together, to try to understand how other teams — particularly Mercedes and Ferrari — were using their energy systems to race each other, as well as to see how the new Pirelli tires performed on a tricky, cool track.

But that is no substitute for accruing real racing data. McLaren, previously F1’s leading team, is frustratingly hamstrung in its quest to return to the top.

The points gap is large but not yet terminal. Eighty points from two races sounds severe, but with 20 races remaining and the constructors’ title decided over hundreds of points, a reliable McLaren running at the front could close the gap. The more pressing problem is the data deficit because every lap a competitor completes is information McLaren doesn’t have.

Gaps in points can be recovered, but gaps in development understanding are harder to claw back.