Bottas says Cadillac sometimes struggles to understand its problems after Austin DNF

Valtteri Bottas saw encouraging pace from Cadillac in Austin, but a suspected power-unit issue ended his United States Grand Prix. After the race, he said the team sometimes did not understand what was going wrong.

It was Bottas's ninth retirement of the season; eight of the nine were linked to technical problems. He said the number of issues made it impossible to get a clear read on the season and that Cadillac still had much to learn.

Both Cadillacs briefly mixed with Aston Martin and Williams before falling away. Bottas said their pace had at times been close to some rivals. Sergio Perez separately said the timing of blue flags around his pit stop cost him race time.

Bottas credited the cooler conditions and cloud cover with helping Cadillac, and hoped the next race in Mexico would be better for the team.