Sebastian Vettel explains reasons for second pit stop

Advantage Mercedes as Ferrari falters (1:33)

Jonathan Legard looks back on a disastrous race for Ferrari, while rival Mercedes seals a 1-2 in Spain. (1:33)

BARCLEONA, Spain -- After a second pit stop dropped him from second place to fourth at the Spanish Grand Prix, Sebastian Vettel explained he would not have made the finish had he mimicked his rivals and attempted a one-stop strategy.

Vettel got up to second place at the start of the race but lost two positions when he made a second stop under a Virtual Safety Car period with 25 laps remaining. The switch to a new set of medium tyres did not offer a performance advantage over his rivals and he failed to repass Max Verstappen, despite the Red Bull driver struggling with a broken front wing endplate.

Asked why he adopted a two-stop instead of a one-stop, Vettel said his rate of tyre wear was too high for him to make the end of the race.

"We couldn't make the tyres last so for us and it was clear we had to come in again," he said. "I think it was the right thing to do.

"If you look from outside it's easier, but inside the car, we were going through the tyres too quick. Therefore we were not able to stay out for another 25 laps. Even in the end, with a fresher set, I wasn't able to attack until the end."

Part of the reason the wear level on Vettel's second set of tyres was on the limit was because he made his first pit stop on lap 17. Ferrari was attempting to cover off Valtteri Bottas behind, who may have tried to undercut him by pitting earlier, but Vettel's early stop tied him to a one-stop for the rest of the race.

Teammate Kimi Raikkonen stayed out longer in an attempt to one-stop before a reliability issue struck on lap 25 and took him out of the race. When asked why Raikkonen was one-stopping and he was two-stopping, Vettel said it was down to the timing of the first pit stop.

"Obviously we had Valtteri behind and he was a lot faster, so we had to cover and we didn't want to lose the position," he said. "I guess Kimi was in a bit of a different position and could choose whatever he wanted to do, so he explored trying to stay out. Obviously he then had to retire so we never saw what would have been."

But Vettel said there was no escaping the fact that Ferrari was simply outperformed by Mercedes in Spain.

"Bottom line is we're not quick enough to win. That's what we have to address. Not did we have a disadvantage here, was that the case, was this the case, did the Safety Car help or not? In the end we weren't quick enough and our tyres didn't last as long as others.

"Otherwise I stay out, stay in front of Valtteri and finish second. It wasn't an option and we finished fourth. We even got lucky with the VSC otherwise we would have been miles behind Max. Not sure what the gap was to Daniel. That was the case today."