The series has switched to a smaller, lighter wheel nut with its next generation cars to make it easier for teams to use electric rattle guns between sessions.
However the new nuts proved problematic during testing with teams facing two seperate issues.
One was the retaining clip on the back of the nut that holds it inside the rim, the original design of which proved ineffective.
The other was spindle tolerance when the wheel hub was hot which made it difficult to fit a cold wheel.
Solutions to both issues have done the rounds of the paddock, with re-machined wheels expected to fit better during hot stops.
As for the nut itself there are two revised designs, one from Erebus Motorsport and one from Triple Eight, that have been shared among the teams.
The Triple Eight design is thought to be an adaption of the original design with a deeper groove and stronger circlip to hold the nut in the rim.
The Erebus design is understood to differ more from the original with the slots at the rear of the nut removed.
The solutions won't be put to the ultimate test in Newcastle this weekend given stop times will be dictated by refuelling rather than tyres.
A far sterner test awaits at the Australian Grand Prix later this month where all stops will be for tyres only.
