There are two main forms: stage rallies and road rallies. Since the 1960s, stage rallies have been the professional branch of the sport. They are based on straightforward speed over stretches of road closed to other traffic. These may vary from asphalt mountain passes to rough forest tracks, from ice and snow to desert sand, each chosen to provide an enjoyable challenge for the crew and a test of the car's performance and reliability.
Starting in 2011, rules for WRC cars changed to be more restrictive. Now regulations were derived from Super 2000 cars with a different aerodynamic kit. The cars were smaller models (there was no longer a minimum 4m length), with a 1600 cm3 direct injection turbo-charged engine with a 33 mm diameter air restrictor and a maximum pressure of 2.5 bar absolute (this will limit torque to about 400 N.m or less).
In February 2015, The National Film & Television School in England premiered one of their graduating films called "Group B" directed by ex-rally driver Nick Rowland. The film, set during the last year of the Group B class of rally tells the story of a young driver having to face a difficult comeback after a 'long and troubled absence'. The young driver is played by Scottish actor Richard Madden, and his co-driver played by Northern Irish actor Michael Smiley.
Between 1997 and 2010, the regulations mandated that World Rally Cars must have been built upon a production car with a minimum production run of 2500 units. A number of modifications could be made including increasing the engine displacement up to 2.0L, forced induction (including an anti-lag system), addition of four wheel drive, fitment of a sequential gearbox, modified suspension layout and attachment points, aerodynamic body modifications, weight reduction to a minimum of 1230 kg and chassis strengthening for greater rigidity. The maximum width was set at 1770 mm while front and rear tracks shouldn't exceed 1550 mm.
Rallying became very popular in Sweden and Finland in the 1950s, thanks in part to the invention there of the specialsträcka (Swedish) or erikoiskoe (Finnish), or special stage: shorter sections of route, usually on minor or private roads—predominantly gravel in these countries—away from habitation and traffic, which were separately timed. These at long last provided the solution to the conflict inherent in the notion of driving as fast as possible on ordinary roads. The idea spread to other countries, albeit more slowly to the most demanding events.
When rallying really took off in the ’80s and ’90s it spawned a new type of performance car. These cars were built for tarmac and mud stages, so their road-going cousins were naturally well-suited to real world conditions. What’s more, they often had four doors, plenty of legroom and a boot (trunk) in the back. And the best bit? Pretty much anyone could buy one and, depending on how deep your pockets were, become Blomqvist, McRae, or Mäkinen.