Former Formula 1 world champion Nico Rosberg believes that Ferrari now has the upper hand on engine power in 2018.
His former team Mercedes has been dominant in recent seasons, winning the driver and constructor titles for the last four years.
But this year the Silver Arrows appear unable to stamp any sort of domination on the championship and have been struggling to match their rivals on pace.
"I know from an insider source why Ferrari is so strong," Rosberg told Germany's Bild newspaper this week.
"They have found more power from their engine. The turbo has been upgraded and more recharging is happening for additional power," he explained.
"It's a small advantage at this time but Ferrari has done a good job."
Even so, Rosberg said he still expected Hamilton to emerge triumphant over the Italian scuderia at the end of 2018.
"I keep thinking that Lewis will get the title. Mercedes is incredibly strong as a team," he said.
Former childhood friends when competing together in junior categories, Rosberg and Hamilton famously fell out during their time together at Mercedes.
While Rosberg has said he would like to repair their former friendship in due course now that he's retired from Formula 1, the 33-year-old isn't above still taking a dig at his former rival now and again.
This week he took issue with Hamilton's suggestion that Ferrari's Kimi Raikkonen had deliberately crashed into him at the start of Sunday's race.
"Kimi was out there and just completely messed it up, braked way too late, locked up and torpedoed into Lewis," Rosberg said on his YouTube channel.
"It is unusual for Kimi because usually those kind of things don't happen to him, so it's a bit strange. But definitely not on purpose."
Hamilton himself subsequently retracted his comments, saying on Instragram: "Sometimes we say dumb shit and we learn from it," adding "It was a racing incident and nothing more.
Rosberg also questioned Hamilton's new-found zeal for football in the wake of England's progress in the World Cup tournament.
Hamilton said he already had plans to be in Russia should the national team make it through to the final on Sunday.
"I played football as a kid, I was passionate about it, I would collect the stickers, the magazines," Hamilton said last week. "Watching on the edge of your seat, the passion – it’s crazy, it’s like it’s in your DNA. It is so exciting.”
But Rosberg said that Hamilton's comments and a photocall where he was in full football strip kicking some balls on pit lane were not for real.
"Lewis is not really a football fan," he told Bild. "It's all a bit of a show. That's part of his image."
We're sure that's not a case of sour grapes on Rosberg's part, despite the fact that England are still in the play-offs while Germany crashed out at the group stage for the first time since 1938...