On lap 21, Fernando Alonso brought his Aston Martin into the pits after repeatedly reporting a loss of speed on the straights. It was his sixth retirement of the 2026 season. Honda said its data showed no engine fault, leaving a gap between Alonso's report from the cockpit and the manufacturer's initial diagnosis.
The trouble had started before the race. Aston Martin fitted a new power unit before Alonso reached the track, then found an oil leak on the first day. Honda had already seen unusual lubrication-system data during FP2. Some components were changed overnight, and the team partly reversed the original switch by fitting parts from the previous specification.
That brought fresh power-unit allocation and penalty risks. The team had little room to spare.
A warning had appeared before the basic event. Honda still says the new engine is suitable for the rest of the season.
During the race, Alonso could fight only with Valtteri Bottas. Sergio Pérez's Cadillac pulled away by more than one second per lap. The gap stood out on Baku's long straights.
Alonso told the team several times that the time loss against the American car was abnormal. He then brought the AMR26 into the pits.
Honda F1 chief Shintaro Orihara said the available data showed no engine abnormality. The manufacturer plans to review maintenance work and factory information, as well as engine power, energy management and GPS data. That review has not settled why Alonso chose to stop. Motorsport.com reported that he made the decision after the radio exchanges.
A wider Aston Martin problem also emerged over the weekend. In qualifying, vibrations caused Alonso to lock his tyres in the second sector. His attempt had been close to both Audi cars, despite their practically new car package in Baku.
The result points to a stronger Aston Martin chassis since Hungary. The power unit introduced at the Dutch Grand Prix remains a separate concern.
Top speed made the problem harder to miss. Formula 2 cars reached a higher speed in Baku than the AMR26. The Honda engine had also looked vulnerable in Monza.
That comparison does not prove what caused Alonso's retirement, but it helps explain why Cadillac's advantage looked so large.
Honda said the irregular oil-system signals appeared during FP2. It identified the cause and replaced the affected parts. The manufacturer said no further engine issue appeared in FP3, qualifying or the race.
Honda so considers the new unit ready to stay in service until the end of 2026. RacingNews365 reported that the lubrication-system problem emerged before the race weekend had fully developed. The reliability concern came first.
Aston Martin changed power-unit components before the race, and Alonso reported behaviour he considered abnormal. The car lacked straight-line speed against Cadillac and even Formula 2 machinery.
Honda's data currently supports the engine. The retirement shows that the car as a whole was not delivering an acceptable result. Checks of power and energy management must explain the lost pace before Honda's confidence can settle the issue.
