In Malaysia, McLaren-Honda team figures including champion drivers Fernando Alonso and Jenson Button extolled the progress made in the fortnight since Australia.
Now, according to Germany’s Auto Motor und Sport, an actual number has been put on the improvement of the burgeoning Honda engine — 25 horse power.
But "We are still over 100hp behind," a McLaren team member is quoted as saying.
The Woking-based team has also been pressing ahead with car developments that were delayed due to the constant stream of reliability issues.
Auto Motor und Sport said the MP4-30 is now sporting a new nose, ’S-duct’, floor and sidepods.
But McLaren is expecting its progress to be hidden this weekend by Shanghai’s long straights and cold weather.
"I don’t think our package will be as well suited here as it was in Malaysia," admitted Alonso.
And team boss Eric Boullier said the second race of the forthcoming double-header, in Bahrain, is also unlikely to suit the 2015 package.
"We are fully aware that the next two races probably won’t show quite the same rate of improvement as we witnessed at Sepang," he said.