While world champions Red Bull got off to an imperious start to the sole pre-season test, the team's key rivals were left to wonder how far behind they are.
After Max Verstappen set the pace, with Lewis Hamilton sixth and George Russell just ninth overall in Bahrain, Mercedes' engineering boss Andrew Shovlin insisted the "performance picture" is "blurred".
"It's impossible to say where we stand," he added, "but we've already identified several key areas where we can find some performance."
Red Bull's Dr Helmut Marko observed that the new Mercedes looks "restless".
"There is no bouncing, which is good news," said Mercedes team boss Toto Wolff. "It's a good starting point."
The Ferrari drivers were third and fourth fastest after day 1 of 3, as new Aston Martin recruit Fernando Alonso turned heads with the best time behind Verstappen.
Even Red Bull technical guru Adrian Newey has his eye on the green car.
"Mercedes, Ferrari and maybe Aston Martin," he answered when asked who Red Bull's main rivals could be in 2023.
Newey's Red Bull colleague Marko also admitted his surprise that Ferrari - unlike Mercedes - is still struggling with the ground effect-caused 'porpoising'.
New Ferrari boss Frederic Vasseur played it down.
"It's not at all like it was one year ago when it bounced like a kangaroo," said the Frenchman.
"We have some parts of the track that are a bit more bumpy than before, especially turn 1. It's a different issue," Vasseur added.
He insists it is "too early to judge" the 2023 Ferrari's performance.
"For now the most important thing is to gain mileage, and so far everything is going according to plan," said Vasseur.
The new Ferrari was also attracting attention for various creative interpretations of the regulations, including front wing winglets and mysterious air channels.
"You probably know that all the teams are constantly in contact with the FIA," Vasseur said, playing down the controversy. "We are exactly the same, so we don't have any problems at all."
As for the strange 'dimple' in the nose that depressed only at high speed in Bahrain, Ferrari explained that it is a manufacturing fault that will be fixed.
Vasseur has also made his first high-profile decision since replacing Mattia Binotto, with strategy boss Inaki Rueda heading back to the factory.
His replacement is a promotion - Ravin Jain.
"We are only working on a few details," said Vasseur when asked about how he will respond to Ferrari's high-profile strategy mistakes of 2022.
"The decisions taken are just the tip of the iceberg," he added. "The strategy depends on a person pressing a button, but there are many processes and systems behind it."
