Both Sebastian Vettel and Mark Webber were unsure why they had problems with their front wings during the Spanish Grand Prix as the pair had to pit for new noses during the race.

14653 - Front wing issues perplex Red Bull pair

Though no damage was obvious visually, both drivers pitted to replace their front wings as they suffered a loss of load. Vettel also had a drive-through penalty for ignoring yellow flags on top of the extra stop and having seen his championship lead erased by Fernando Alonso he admitted he wasn't satisfied with finishing in sixth place.

"It was difficult race and a hard day in the office," Vettel said. "I'm not entirely happy, we could have finished maybe one position higher up, but we had a good recovery in the end. We were definitely stronger towards the end of the race and it was good fun, but when it's up and down and up and down, it's quite difficult.

"I don't know what the problem was when we had to change the nose of the car; I wasn't sure if I had damage or something stuck at the front - maybe a piece of rubber or something. I tried another lap, but it wasn't the right thing to do, so we decided to come in and change the nose to make sure. It lost us some time, but it was the right thing, as I was told there was some damage to the front left of the wing."

Webber was the first of the two to suffer the problem and he said the overall pace of his car was also surprising.

"It was an interesting race and a difficult first lap," Webber said. "I don't know where I got damage to my front wing, but I had to pit for a new nose. I lost a lot of time with that - and on the few laps before when it started playing up. We had to pit and when you're out of position here it's tough - you have to look after your tyres and when you catch people your tyres get killed, so it's chicken and egg. If you push past them, you have to pit earlier and commit to another stop. It was a mystery with the pace; I was stuck behind Force India, you see the McLarens weren't doing so much and Seb was just chipping away."