Mercedes investigating Russell's myterious straight-line deficit at Silverstone and Spa

Mercedes says it is urgently investigating the unexplained straight-line performance deficit that continues to hamper George Russell after Andrea Kimi Antonelli claimed his sixth pole position of the Formula 1 season at the Belgian Grand Prix.

Antonelli continued his superb Spa-Francorchamps form by converting his pace from Friday and Saturday practice into another pole position, beating Max Verstappen by three tenths of a second. Russell, meanwhile, qualified fourth before being promoted to third on the grid by Lando Norris' 10-place penalty, but once again lost significant time on the straights compared to his team-mate.

Trackside Engineering Director Andrew Shovlin admitted the issue remains unexplained and is now one of Mercedes' top priorities.

"Well done to Kimi, George and the team on another pole position and P3, which gives us a great chance of a good result tomorrow," Shovlin said.

"It's a good outcome after what has not been a particularly straightforward day or weekend so far."

Shovlin revealed that Antonelli and Russell experienced contrasting practice sessions before Mercedes made only minor setup adjustments ahead of qualifying.

"Kimi's first run in FP3 was good, but when he pushed a bit harder in the final run, the rear tyres dropped away. George started the session a little off the pace but his final lap on the new Soft tyre was solid; there was a little more time to find in a couple of corners but also some on the deployment in the run to the final chicane."

Both drivers initially struggled with rear grip as track temperatures increased during the opening phase of qualifying.

"Both drivers were reasonably happy with the balance going into qualifying, so we made only minor changes to the set-up. Our first laps with both were not great; the track was a little warmer and we were losing a bit of rear grip. We were able to get on top of that for Q2 onwards though."

However, while Antonelli steadily improved on each successive set of tyres, Russell's recurring straight-line problem again proved costly.

"Unfortunately, George continued to suffer from poor deployment into the final chicane which ultimately cost him a position on the grid tomorrow; P3 is a strong effort considering that," Shovlin explained.

"We're investigating what's causing this as a priority as there is a clear loss that we cannot explain by driving style."

The comments reinforce Russell's own assessment that the deficit is not related to his technique behind the wheel. Instead, Mercedes believes there is an underlying issue preventing the Briton from matching Antonelli's straight-line performance, despite both drivers using the same specification of car and power unit.

By contrast, Antonelli extracted the maximum from the W17 throughout qualifying.

"Kimi meanwhile put together a nice sequence of new tyre runs; he was finding time with each set and put together a very impressive lap on the final run to secure pole."

Looking ahead to Sunday's race, Mercedes expects tyre management to be the decisive factor around Spa-Francorchamps, where overtaking opportunities are plentiful.

"This is a track where the long straights will make overtaking relatively easy, so race pace is going to be vital," Shovlin said.

"The key to unlocking that is looking after the tyres well. We don't have as much long-run data as we'd like but normally, we are slightly stronger on Sunday, so hopefully that trend will continue and we can secure a good result for the team."