McLaren team figures believe the recent flexible bodywork saga will have taken the shine off Red Bull's earlier dominance.
At F1's last outings in Spa and Monza, where new FIA compliance tests came into effect, the RB6 was no longer the stand-out dominant package it had been at earlier events.
But Red Bull already expected to struggle at those high speed circuits, due to its less powerful Renault engines.
In light of the team's dominance on twisty tracks like Monaco and Hungary, therefore, this weekend's racing on the Singapore street circuit might be seen as a litmus test of the true effects of the FIA's flexibility clampdown.
"I think a lot has changed since that race in Budapest -- not least, some quite hefty revisions to the rulebook regarding bodywork flexibility," said Jenson Button.
Team boss Martin Whitmarsh agreed: "Singapore is likely to give us a much clearer idea of the respective pace of the leading teams after two less-representative events in Belgium and Italy."
Chief race engineer Phil Prew is also hoping Red Bull will be closer to the rest of the field in Singapore this weekend.
"The legality clarification and changes that we've all made in response to that could well influence it (the pecking order)," he said during Wednesday's Vodafone phone media conference.
"We're optimistic that the gap, which was massive by Formula One standards, should well have reduced," added Prew.
He said he now feels all the teams are racing on a level playing field.
"The advantage that was felt to be gained by Red Bull and Ferrari in Hungary will be harder to exploit," confirmed Prew.