Three-time Formula 1 world champion Sir Jackie Stewart feels Sebastian Vettel remains the favourite to win his fourth consecutive drivers' title with Red Bull despite Mercedes making rapid progress in the 2013 season.
Championship leader Vettel scored 172 points in the first 10 races of the season, leaving behind Lotus' Kimi Raikkonen (134 points), Ferrari driver Fernando Alonso (133) and Lewis Hamilton (124), who is fourth in the standings in his first year with Mercedes.
Stewart says Mercedes look a competitive lot especially after the win in Hungary but he would put his money on Vettel for the title, ahead of season's second half beginning with the Belgian Grand Prix this weekend.
"Lewis Hamilton drove an extremely good race at Hungary. He was both fast and aggressive and the Mercedes certainly worked that day. However, I would still have to bet on Vettel for the title as Mercedes have not yet stabilised their performance and that applies to both Lewis and to Nico Rosberg," Stewart told IANS from his Buckinghamshire base.
Mercedes have raised expectations with the way they managed their rear tyres at the hot and humid Hungaroring. They scored 136 points in the last five races, only 10 less than leaders Red Bull. There was not a big points gap between Vettel and Hamilton, who collected 74 points to the German's 83.
"It's very clear that the Mercedes, under the direction of Ross Brawn, are constantly getting more competitive. But I am sure that Adrian Newey will still keep Vettel and Red Bull competitive enough for the constructors' and drivers' championship," said Stewart.
Asked about Alonso still being a title contender, the Scot said: "The Ferrari has to be a better car before Alonso can seriously look at the championship and I don't think that can be achieved this year."