MONTREAL, Canada - Sebastien Vettel has for three years been winning Formula 1 races all over the world with ruthless efficiency - but not in Canada.In chalking up a Drivers' championship hat trick he has added his name to the winners' list on almost every track on the circuit; the few that have eluded him include the Canadian GP here in Montreal.The demanding street circuit, with its long straights and slow, tight corners, does not suit Vettel's Red Bull but his failure to win there has had little to do with his car.WIDE SLIDEIn 2011 he had the race at his mercy when he charged into the lead after a long rain delay only to make a mistake on the last lap, sliding wide and allowing Jenson Button to overtake him for the flag.Read DIETER RENCKEN's preview of the Canadian GP"Obviously one of the craziest moments was in 2011," he recalled as he looked ahead to Sunday's race. "I made my first mistake of that race and it cost us the win - but that's racing."Determined to make amends, Vettel started 2012's GP from pole and led the early part of the 70-lap race but he lost pace over the final laps and was lucky to finish fourth after skimming the wall near the end.Although he's leading the 2013 World standings with 107 points, winning on Sunday is anything but assured. There have been four winners from the six races of 2013; only Vettel and Fernando Alonso have won twice.Unlike Vettel, Alonso has tasted victory at the Gilles Villeneuve circuit, winning in 2006 on the way to his second World title with Renault. He is third in the title race, 29 points behind Vettel, but Ferrari has not won in Canada since 2004, when Michael Schumacher was driving.UNPREDICTABLEKimi Raikkonen, the 2007 World champion, is second on 86 points. He won the season-opener in Australia for Lotus and was second in three consecutive races before fading to 10th at the most recent, Monaco. He won in Montreal in 2005 but said it remained one of the most unpredictable events on the F1 calendar."Many times the race has been quite a lottery - various things affect it." he said. "The weather can change a lot, sometimes the tyres or the track aren't working very well, sometimes there are a lot of pace-car periods or sometimes another driver runs into the back of you when you're waiting at a red light."If recent form is any guide, Mercedes could be the team to beat; its Nico Rosberg has set the fastest times in qualifying at each of the previous three races and won in Monaco."Monaco was a fantastic weekend for the team - I'm so proud of the victory there," Rosberg said. "We'll be hoping to maintain that momentum in Canada." DEFENDING CHAMPHamilton, with pole in China and two podium places so far in 2013, is a Canadian GP specialist, winning in 2007, 2010 and 2012. He is tied with Nelson Piquet for the second most wins in Montreal, trailing only Schumacher, who has a record seven."The circuit is really special," Hamilton said. "It's very high-speed, great fun to drive and it's definitely a track where late braking helps."It's not too far off a Monaco-style circuit where you need a similar set-up to bounce off the kerbs so we should be quite competitive, although looking after the tyres will be our main challenge." Stay with Wheels24 for the 2013 Canadian GP weekend.