V8 Supercars organisers have mandated a minimum number of pitstops for this weekend's Sandown 500 endurance race amid ongoing debates over fuel parity.
All competitors must make at least four fuel stops during Sunday's event, which is the first in the series' long-distance triple crown with Bathurst and Surfers Paradise.
The new works Nissans and Erebus-run Mercedes have struggled to achieve the same fuel economy as the established Fords and Holdens this year.
The teams all agreed to allow Nissan's James Moffat and Michael Caruso and Erebus's Maro Engel to trial a revised E70 fuel blend on the Saturday of the last round at Winton, with Moffat and Caruso giving the Altima a historic one-two.
The whole field will now return to the standard E85 fuel for Sandown, with the series' general manager of motorsport Damien White feeling the pit ruling is a better option.
"The commission believes this is the appropriate method to minimise the effect of the current fuel economy variance that exists ahead of these three critical endurance events," White said.
"It was determined that while there was no material gain in power or performance using the lower blend of ethanol fuel, a more effective approach was to ensure everyone was racing on the same basis by mandating the number of pitstops."
The series will decide on fuel and pit options for Bathurst and Surfers following Sandown.