The FIA World Touring Car Championship (WTCC) was launched in 2005. It is one of four world championships sanctioned by FIA and regarded as the top category of touring car sprint race series in the world.

Its basic event format consists of two 50km or 30 minute races per round. For 2011, the calendar initially had 12 rounds (24 races) but then the Moroccan round was cancelled later. At the time of writing - mid-March, a replacement round in Europe is under consideration.

Even though a round in the African continent was lost, the championship still tours around other continents, South America, Europe and Asia. It made the first visit to Japan in 2008 and has provided the opportunities to really feel the allures of WTCC for many motor sport fans in the country through the events at Okayama International Circuit for the last three years. From 2011, the Japanese round will move to Suzuka Circuit (the east short course) and the expectation for a good show at the new venue is already high.

WTCC is also known as a 'combat sport on race tracks' and its biggest appeal is the restless fierce battles shown everywhere on the track from start to finish, which explains the reason why the number of its followers has been growing so rapidly in Japan. Contact between cars is a part of life here but those aren't outrageous fights, so the spectators can enjoy the skillful race craft of world class drivers. You can closely watch superb technique of the drivers who always keep aggressive attitude, under certain rules and common sense. That's what makes WTCC so attractive.

Behind such entertaining races, there are the sporting regulations which are well thought out to facilitate close battles.

Firstly, there is the reversed grid system. It has been adopted for years to decide the starting grids of Race 2 but the system is now revised for the new season.

In the past, the top eight finishers of Race 1 were placed in reversed order on the starting grid for Race 2. Under this old system, however, the driver could deliberately back off in Race 1 to obtain a better grid position for Race 2.

To prevent this, the new system decides the grids for Race 2 by the result of the first section of qualifying session, giving the top ten qualifiers the first ten grids in reversed order. In the WTCC's qualifying format, all competitors run in the first section and then only ten fastest drivers are allowed to go on to the second section. And this final section decides the top ten grids for Race 1, in the same way as before, followed by other drivers who had knocked out at the end of first section. It should be very difficult for a driver to control his position in the sessions, aiming to sit on a good starting grid for the second race, as everyone tries to break into the top ten.

Secondly, the compensate weight system also contributes to create interesting competitions. The system, introduced in 2009, gives a handicap weight to each car model, the FIA's homologation number to be precise, according to the results from previous rounds. To compensate the performance gaps between car models, the amount of weight for each model is decided by a calculation using lap times in the qualifying sessions and races. Needless to say, if a car model is faster than others, it will be given heavier weight though the upper limit of such handicap weight is defined.

The performance adjustment like this may sometimes lacks transparency. But the WTCC's system shows the performance gap in clear numbers, while the calculating formula may be a bit complicated, and all official documents which describe the process to decide the amount of weight for each car model are disclosed on the web.

There are two types of teams in WTCC, depending on if a team is registered as a manufacturer. The registered teams are considered as 'factory' outfits and eligible for the manufacturers' championship, while their drivers still contend for the drivers' championship.

The non-registered teams are regarded as 'privateers' and aren't involved in the manufacturers' championship. Instead, they hotly contend for the YOKOHAMA Trophy for drivers and teams which only non-manufacturer teams are eligible for.

The drivers' championship points are given to the top ten finishers of each race, regardless of the type of team a driver belongs to. The point system is identical to that of Formula One.

The system for YOKOHAMA Trophy is basically the same but the points are given to only eligible drivers for the finishing order among them, from first to eighth. For the final round at Macau, the championship points will be doubled. Therefore, the fight for the trophy may become hotter in the season closing races.

Yokohama Rubber has been the official tire supplier of WTCC, the pinnacle of touring car sprint race series, since 2006. During the Portuguese round in 2010, the Japanese company has passed a milestone of the 100th race since it started supplying tires for the series and the organizers and teams made a compliment once again for consistently providing high quality ADVAN racing tires.

The exclusive supply contract has already been extended until the end of 2012 and the requirement is always the same. The single spec tires must provide the equal competitiveness for different types of cars, both FR (rear wheel drive) and FF (front wheel drive), which compete against each other in WTCC.

In this respect, Yokohama has won the confidence from the organizers, teams and the world class drivers, utilizing the know-how earned from its longstanding worldwide motor sport activities and the technical ability to develop appropriate tires.

WTCC is know as an environment-friendly race series and, following its policy, Yokohama began to supply the orange oil blended Eco Racing Tires from the 2010 season. The tire achieves a superb environment performance, maintaining the required performance as racing rubbers in a high level at the same time.

The number of tires that teams are allowed to use in a round is set forth in the sporting rules. The competitors may normally use 12 (3 sets) new dry tires plus 8 (2 sets) used ones but, for fly-away rounds and the first round of European leg, 16 (4 sets) new dry tires are allowed.