A key takeaway from the format announcements of the four Sydney Motorsport Park events is the return of 250km-long races.
Formats and tyres were confirmed for the four back-to-back Sydney rounds, with the first event to commence on October 29.
Formats, tyres confirmed for Sydney events
Fourth Sydney event to feature Additional Driver session
Three of the four events will feature night racing, with the first and second events to feature 125km-long sprints.
The final Sydney event, the Beaurepaires Sydney SuperNight, will be the third round in 2021 to feature 250km-long races.
The season-opening Repco Mt Panorama 500 and NTI Townsville 500 featured two 250km-long races.
All four races were won by series leader Shane van Gisbergen, who has also won four races in Sydney.
Refuelling will return - and critically, so will Dunlop’s new-for-2021 Super Soft compound, which debuted in Darwin.
Drivers will be obliged to use both the Hard and Super Soft compounds in the 250km races.
Ambrose won the first 200-plus-kilometre race in Sydney Pic: AN1 Images
Drivers will have one set of the Super Softs for each race. The Hard tyres are permitted for use in practice and qualifying only.
Given how tough Sydney Motorsport Park is on tyres, and with mixed tyre events previously producing surprise results, strategy will be key.
One qualifying session, an ARMOR ALL Top Ten Shootout, and a 250km race will feature on the Saturday and the Sunday.
Saturday’s Race 29 will be run under lights, and Race 30 in the afternoon.
When lights go out on the Saturday, it will mark the longest race at Sydney Motorsport Park since the 300km-long night race in 2018.
Van Gisbergen also won that race after a thrilling late battle with Scott McLaughlin.
Just nine of the 59 championship races held at the Eastern Creek venue have been 200km or more in length.
The first was in 2003, 11 years after the circuit made its championship debut.
Van Gisbergen won the 300km-long night race in 2018
That day, eventual champion Marcos Ambrose claimed his first round win of the season in the 300km-long race.
Ambrose won the 220km-long Sunday race when the championship returned to Sydney for the season finale.
A 300km-long race was staged in April 2004, but it was red-flagged 10 laps short of its scheduled distance due to heavy rain.
It handed a maiden solo win to Rick Kelly, which doubled as Holden’s 150th round win.
The 2012, 2014, 2015, 2016 and 2017 events were headlined by 200km-long races, with Jamie Whincup winning three of them.