The champion team could not keep its Pirellis intact as effectively as Ferrari and Lotus at Barcelona.
Fernando Alonso got ahead of Vettel in the first pit sequence, and he later fell behind Kimi Raikkonen and Felipe Massa as well.
Vettel insisted he was content with fourth place in the circumstances.
"I think we can be happy with fourth - or at least we have to be," he said.
"The first three cars were a little too fast for us and in looking after their tyres they did a better job today."
He is confident there is no lack of raw pace in the Red Bull.
"If you talk about race distances, then it's a different game," Vettel said.
"I think the car is quick enough, but there's something we do to the tyres to make them wear more.
"Three people did better today so we need to catch up. We are not going to the pace of the car, we are going to tbhe pace of the tyre."
Vettel also believes Red Bull make a strategic mistake by initially trying to pull off a three-stop plan before resorting to four.
"I think we tried to hang on to the three-stop for too long in the race and had to admit towards the end we wouldn't make it," he said.
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