Subaru would be eligible to enter to the World Rallycross Championship next season following changes to the series' engine regulations.
The Vermont Sports Car-operated Subaru Motorsports USA team has contested American-based rallycross events for a number of years, including the inaugural European-style rounds in New Jersey in 2010, the Global Rallycross Championship, the Americas Rallycross Championship and the Nitro World Games.
The majority of events though have taken place under technical regulations that have not been fully in line with FIA rules. Technical rules for the ARX series, which was run for two years by World RX promoter IMG, for example were a hybrid of regulations between the GRC's more open rulebook and the FIA's 279 regulations.
But following extensive consultation with the FIA's technical working group for rallycross, which includes teams, the promoter and the governing body, the FIA has published updated regulations for 2021 that would now allow Subaru to enter the championship.
The 'Custom' engine regulation, which was introduced in 2015, has now been adapted to allow cars with boxer engines - such as Subarus - to compete.
Prior to its introduction, rallycross Supercars had to run an engine block from the same manufacturer as the chassis, but since 2015 the 'Custom' rules have outlined a strict set of dimensions, materials and weights for components in a bespoke in-line, four-stroke engine configuration.
The 'in-line engine design' regulation has now been scrubbed from the 'Custom' engine rules and as of 1 January 2021, a boxer engine will be allowed to compete.
The iconic Subaru boxer motor in 'Custom' trim was previously ineligible as it was unable to meet certain aspects of the 'Custom' rules, and as such changes have also been made to the main bearing width, con-rod bearing width, minimum camshaft and crankshaft weights, along with rules surrounding total engine weight and the centre of gravity above the crankshaft centre line.
Subaru has so far made only a single appearance in World RX, when Norwegian Sverre Isachsen raced for the marque at the Canadian round in 2014.
The Subaru team did win four of the six Americas Rallycross rounds last season with former Formula 1 driver and four-time US rallycross champion Scott Speed, and former World Rally drivers Patrik Sandell and Chris Atkinson, but the squad didn't manage to take the drivers' title with its much-revised WRX STI machine.
While ARX was sharing track time with World RX competitors at Trois-Rivieres in Canada last August, Swede Sandell set the fastest lap times of the event.