The FIA have confirmed new technical regulations for the 2021 FIA World Rallycross Championship.
Most significantly, there have been changes to the engine regulations for next season. Previously, only I4 engines were allowed but the new rules will accommodate boxer type, four cylinder units.
These engines can be used if based on road car block and heads but not if they feature custom made block and heads.
It means that Subaru-based entries such as Subaru Motorsports USA can enter the championship having not been eligible to race in the World RX due to their bespoke engines and the custom engine rule that was enforced in 2015.
Subaru have been racing in rallycross in the Americas Rallycross Championship and won four of the six events last year, however the ARX series no longer exists having ceased at the end of 2019.
Other changes include window nets and internal restraint nets becoming compulsory. Both nets must be releasable by the driver when belted in.
From 2022, other engine rules will come into effect such as a limit of just one homologated anti-lag system with tighter controls on the layout of systems.