Lewis Hamilton said he was still struggling with his car and its braking despite finishing a robust third for Mercedes in Sunday’s Canadian Grand Prix.
The 28-year-old Briton, who led the race for three laps but struggled in the closing stages, said he still lacked complete confidence in the car.
“It has just been a work in progress. We haven’t cured anything. It has been a long period of time since Barcelona where there was big trouble there.
“We have picked up a couple of techniques and worked on it, which helps.
“We still need to improve (the braking) and that is where Fernando (Alonso) was catching me everywhere.”
Alonso, who started sixth, caught and passed Hamilton in the closing stages of the race when his Ferrari appeared to have more performance in hand than the Mercedes.
Hamilton added: “He was massively quick and difficult to keep behind. I tried my best and got closer once he got behind me, but he was too quick.”
Apart from the problems with the braking, Hamilton admitted his car felt as if it was lacking grip during the race.
“I guess it was just grip, as the car was pretty fantastic,” he said.
“I am assuming those guys were better with that. Fernando seemed to be quicker in the lower-speed corners.”