Ground effect is a term applied to a series of aerodynamic effects used in car design, which has been exploited to create downforce, particularly in racing cars. This has been the successor to the earlier dominant aerodynamic theory of streamlining. American racing IndyCars employ ground effects in their car's engineering and designs, similarly they are also employed in other racing series' to some extent, however Formula One for example, as well as most other racing series, primarily across Europe, use design constraints due to specific regulations (or complete bans) which affects and limits its effectiveness.