Toto Wolff concerned by 'painful' Malaysia pace

Mercedes boss Toto Wolff says Mercedes' lack of pace during the Malaysian Grand Prix was "painful", despite his team increasing its lead over Formula One title rivals Ferrari in both world championships.

Lewis Hamilton's second-place finish in Malaysia extended his advantage over title rival Sebastian Vettel to 34 points, while Mercedes moved closer to sealing a fourth consecutive constructors' championship by increasing its lead over Ferrari to 118 points.

But Wolff has taken little satisfaction from the result, pointing towards the significant pace advantage held by race winners Red Bull, and Ferrari, with Vettel charging through the order from the very back of the grid to finish fourth.

"We benefitted in the championship from the misfortune of Ferrari but we didn't have the pace to challenge either Red Bull or Ferrari and this is what remains the underlying feeling with all of us", Wolff said. We need to understand why we underperform on certain circuits and in certain ambient conditions.

"It's these moments that make you progress. I had the best race debrief in five years right now, this is one of the feelings I have, because it's just so painful.

"This is a sport where you take no prisoners. We take the points and Ferrari would have done the same, but somebody else's misfortune or underperformance doesn't cheer me up at all. We're looking at our own performance, our own level of performance, whether it was good enough or better than anybody else's."

Mercedes struggled on Friday and opted to split its aerodynamic packages between its drivers. Hamilton, running the older spec W08, fared better as he claimed pole position and finished in a comfortable second, while Bottas struggled for pace in both qualifying and the race and crossed the line in a distant fifth.

"I think that Lewis extracted the maximum in qualifying, benefitting from cooler temperatures and obviously on one lap he's a real force. Maybe on one lap the underlying problem that we had in the car wasn't as obvious or as visible as it was in the race. This is the underlying feeling that exists at the moment, how can we fix our issues?

"Benefitting from Ferrari's problems in the championship shouldn't hide that they have caught up 30 seconds this race. I guess there's more problems that come together and cause a lack of performance. One of them is certainly very high ambient temperatures and specific circuit characteristics. There might be some more circuits before the end of the year where we need to understand."

Wolff hopes Mercedes form in Sepang was nothing more than a blip, and reckons next weekend's Japanese Grand Prix -- a power-hungry circuit expected to suit the characteristics of Mercedes' W08 -- will provide a different outcome.

"I'm very much looking forward to Suzuka to see how the car behaves there because it should be completely different. But every time we put the car on a circuit and drive it, the more we learn. Hopefully we are not having outliers of underperformance like this weekend."