Sebastian Vettel is not getting carried away about Red Bull's form ahead of this weekend's Chinese Grand Prix.
Although Vettel starts the Shanghai weekend as favourite for victory after his win in Malaysia, the German is taking nothing for granted.
"I'm only 22, but I've learned there are no guarantees in life," Vettel told the BBC after practice, where he finished as fifth quickest.
"We still have to work hard. We have one of the best cars. I think that's something we can be proud of, but we still have to work."
Vettel admitted he is hoping his team will have an F-duct system soon, after seeing McLaren set the pace in practice on Friday.
"Today it looked very close," he added. "Apart from McLaren, all the other teams do not have an F-duct yet, at least one that works as well as the McLaren one.
"It's something nice to have, because there's no easier time to gain lap time than to drive on the straight, but we'll see. Hopefully soon we'll have something similar."
But the Red Bull driver said he was pleased with his day's work ahead of qualifying.
"At the end of the day I think we had a good day. No big issues with the car, no problems."