NEW DELHI, India - Formula 1 championship rivals Sebastian Vettel of Red Bull and Ferrari's Fernando Alonso both have cause for optimism ahead of the Indian Grand Prix, as the title fight winds down to four races.Vettel's victory in Korea made it three straight Grand Prix wins, snatching the drivers' championship lead from Alonso, who had led by as much as 40 points before Vettel's winning streak.The Indian track, the Buddh International circuit, has similar characteristics to that of Korea - long straights in the early part of the lap followed by more twisting, technical sections.WIND TUNNEL WOESThe Buddh circuit has fast, sweeping corners, which usually suit Red Bull more than its rivals. Vettel is eager to get back on the Indian track where he won the inaugural race in 2011.Vettel said: "I loved the track layout in 2011, but not just because I won the race. "The course is the second quickest of the year after Monza. There is a lot of elevation change around the lap which adds to the fun...it's like a roller coaster."It really has emerged as one of the most challenging circuits on the calendar for the drivers," he said.Ferrari, however, believes it has cured its wind tunnel problems and expects that should allow it to catch up to Red Bull over the remaining races.Ferrari has altered its wind tunnel after finding its upgrades at the past two races haven't worked on the track as they did back at the Maranello headquarters.Ferrari chief designer Nicolas Tombazis said: "We got some very interesting answers which we believe will allow us to recover from those problems and so, our aim in this forthcoming Indian GP, will be to make up the ground we have lost." He suggested the problem may lie in scale - the model used in the wind tunnel is not the same size as the actual car and the difficulty of making air in the tunnel identically replicate open-air conditions."The way aerodynamics works on a modern F1 car is hyper-complicated, based on the interaction of various components and very small details, therefore it is easy to make a mistake. "We have had problems in some areas, but that does not mean that all our work in the wind tunnel has been worthless," Tombazis said.DIRTY TRACKThe track layout was praised by all drivers during the 2011 race. Its sweeping bends and wide entries into corners encourage different approaches and overtaking opportunities. Overtaking was made difficult by the dirtiness of the track off the racing line and organizers have reportedly made efforts to alleviate that problem with track cleaning.A second DRS overtaking zone has also been introduced for this year's race, while teams have received assurances there will be no repeat of the 2011 power failure in the paddock, which caused a panic in the garages.While the challenge for the driver title appears to have been reduced to Vettel and Alonso, the fight over the standings in the constructors' championship - where a difference of just one spot can make millions of dollars of difference in prizemoney - remains tight.Ferrari, McLaren and Lotus are separated by just 35 points in the fight for second and third, while fifth-placed Mercedes is only 20 points ahead of Sauber.