The more common perception in the F1 paddock so far this year is that while the silver W05 is a tidy single seater, its clear dominance is being fuelled mainly by its vastly superior turbo V6 'power unit'.
Red Bull, meanwhile, is apparently only managing to stay relatively competitive amid engine supplier Renault's problems due to the once again field-leading car design efforts of Adrian Newey.
But Aldo Costa, the Mercedes car designer, insisted to Germany's Auto Motor und Sport that his W05 is "about on par with Red Bull".
"There are certain corners, especially the fast ones, where Red Bull is better than us," he acknowledged, "but in other places it is us with the edge.
"According to our measurements," the former Ferrari technical director added, "Ferrari is behind us."
Costa also hit back at suggestions F1's new engine rules have made the sport too slow.
Actually, he said it is "quite simple" to calculate precisely why laptimes are slower in 2014, explaining that the engines are in fact compensating for most of the losses.
"The cars are 50kg heavier (than in 2013)," he started. "This alone costs 1.5 seconds. The downforce was reduced, which is another half a second," said Costa.
"Add to that the harder tyre, then without these factors we would be faster (than in 2013)," said the Italian.
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