Red Bull resisted opportunities in the last 18 months to sign Lewis Hamilton, Kimi Raikkonen and Fernando Alonso.
Vettel fastest in eventful practice two
"One day maybe I will race alongside Kimi or Fernando," Vettel said.
"It depends how long we stick around. But I am not afraid of that because you want to beat the guys on the track and you want to find out who is the best."
Vettel, who has won the last five races in a row, needs only a fifth place in the Indian Grand Prix to be absolutely sure of the title.
Only Ferrari's Fernando Alonso is mathematically able to beat him, but is 90 points behind with only 100 still available. The Spaniard needs to out-score Vettel by 16 points on Sunday to prolong the championship to the next race in Abu Dhabi next weekend.
Vettel, who was talking in a BBC Sport interview to be broadcast ahead of the race on Sunday, rejected a suggestion that he needs to take on Alonso, Hamilton or Raikkonen in another car to prove his greatness to any doubters.
"You can think about this a lot," he said. "I think we don't have to prove anything. I think we have proven enough.
"We have had three fantastic years. This year has been fantastic. I believe things happen for a reason.
"For sure you need the right package. We had a very strong package the last couple of years. I believe we had a very strong package in 2009, when we finished second in the championship.
"With the experience I have today maybe 2009 would have been different. At the time I did the best I could. I did mistakes, I still do now, but the most important thing is I learn from them.
"We managed to come back [and seal the championship]. It was a bit tight in some places, a bit lucky. We worked very hard for what we have achieved basically, as a team.
"For sure some people will think you have to do this and that. The most important is to prove something to yourself."
Asked how he felt he compared as a driver to Hamilton and Alonso, Vettel said: "It's difficult because I don't know what they do. I can see what they do on the track. I don't know how much time they spend setting up the car, how much they care.
"I'm sure we all care because no-one wants to drive a car that is set up badly, but for sure some people invest more time and some less. I don't think there is a right and wrong, it is what you feel happy with."
Watch the interview with Sebastian Vettel in the build-up to the Indian Grand Prix on Sunday 27 October on BBC One from 0830 BST
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