The two feature races will now be contested over 68 laps each to ensure all cars can make it through the distance on two fuel stops.
Townsville’s Friday sprint remains at 35 laps.
The changes have been made following the latest analysis of fuel consumption numbers from the 2026 season.
Supercars has made a series of tweaks in the lead-up to events this year based on fuel calculations.
It reduced the Sunday race at Taupo by a single lap back in April.
The following month it elected to add six laps and a third compulsory pit stop to the Symmons Plains feature race.
Although intended to add to strategic variability, that format proved polarising as the sheer volume of pit stops dominated the action.
Fuel consumption has increased this year due to the adoption of a revised blend, made up of 85 percent ethanol and 15 percent bio-gasoline.
The remaining Sunday Sprint Cup races at Perth and Ipswich are both thought likely to need tweaking too.
Supercars has meanwhile also been working to ensure fuel economy parity between the brands.
Triple Eight team boss Jamie Whincup said at Symmons Plains the three-stop rule had been added due to the Chevrolet being too thirsty.
The category has run new fuel flow meters across each of the marques at the last two events, as well as mandating a new reporting system from Darwin.
Teams must weigh their fuel churns before and after pit stops and report the numbers to Supercars.
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