Tsunoda had been well-placed to score points in the Monaco Grand Prix last month as he ran ninth with 20 laps to go. But in the final stages of the rain-hit race, he was passed by both McLarens and continued to slip down the order. He eventually finished in 15th as rookie team-mate Nyck de Vries grabbed 12th.
The Japanese racer noticeably struggled with his brakes, voiced his complaints over team radio and ran off the track at Mirabeau as he struggled to manage temperatures. His brakes again caught the attention in Spain last weekend due to the excessive levels of dust they were producing when under heavy load.
Asked by Autosport to explain the situation, Tsunoda said an “efficiency” issue that was exaggerated in wet conditions was long-running at AlphaTauri and had also blighted Alpine-bound Gasly during 2022.
He said: “The brake issues we have are from probably last year. It happened more often towards Pierre rather than me. But this happens to me more [this season].
“Literally, I don't feel any efficiency from braking. It just doesn't warm up, doesn't feel any efficiency so you cannot push as much as I want to in the rain conditions.
“Obviously, that makes the tyres colder, it just goes worse and worse.
“[In Monaco] I had [problems] from FP1, which also affected my qualifying performance as well.
"It's a bit of a shame because I have to do extra build-up compared to other competitors just to warm the brakes, which is a bit unnecessary.”
Tsunoda said the issue was solely a brake material hardware, rather than a calibration problem, that affected the cars independently of his particular driving style.
He instead said it was “more towards the engineering side” when it came to finding a fix, which would enable him to move away from his current excessive use of engine braking to slow down.
Tsunoda, who ranked 12th in Barcelona after serving a five-second penalty for forcing Zhou Guanyu off track, reckoned the team had made gains with the brakes across the double-header with Monaco.
He said: “We changed a little bit the brake approach to have more aggressive temperature and actually we had to slightly manage the brakes this time.
“Actually, that was much better because efficiency was much better than Monaco.
“I think the team did a good job and I’m pretty happy with it so we made a step.”
