Sebastian Vettel's poor performance at the Brazilian Grand Prix has been traced to a sensor problem that was affecting the handling of his Ferrari.
The German, who started the race in second place having qualified 0.096s off eventual winner Lewis Hamilton, finished the race in a distant sixth-place.
Vettel was overtaken by Valtteri Bottas at the start and lost two more positions to Max Verstappen and Kimi Raikkonen on lap four of the race He was able to get ahead of teammate Raikkonen through the pit stops but Ferrari used team orders to swap its drivers around, allowing the Raikkonen to have the chance to attack Bottas and eventually secure third place.
After the race, team boss Maurizio Arrivabene confirmed Vettel had suffered a problem with one of the sensors on his Ferrari.
"Right from the formation lap, we became aware of a problem with a sensor on Seb's car,'' Arrivabene said. "This meant that, for the whole race, he had to run different settings to those we would have normally used and that made the car difficult to drive.''
Reflecting on the race itself, Vettel was unsure Ferrari made the right decision to start on the soft tyres -- the more durable tyre compound -- compared to Mercedes and Red Bull -- who started on the super-softs and were still able to complete a one-stop strategy.
"Well I tried everything but obviously in terms of the result, one, and one being bad,'' Vettel said after the race. "It's just a difficult afternoon. I don't think we were on top of the car today, the tyres. I don't think it was an advantage to be honest starting with the soft, the super-softs lasted a longer time, longer than I think we all expected. But that's how it is.''