Singapore GP: Mercedes unsure how much upgrades have helped car after practice

Mercedes brought a new 'Coanda-effect' exhaust system to Marina Bay.

It is hoped that the upgrades will reap an instant boost in competitiveness, but tyre and brake problems masked the team's pace in the opening 180 minutes of running.

The drivers also insisted again that it will take time to extract the maximum potential from the package.

"There are a lot of new parts on the car and it's just going to take some time to work them in, get the most out of it and understand them so we have to do a lot of analysing." said Rosberg, who was eighth fastest, 1.4s off Sebastian Vettel's pace

"The beginning was okay now but nothing spectacular. That's it, it was a decent start

"You can definitely feel the improvements in various areas, so there are a lot of positives."

Rosberg explained that overheating tyres were Mercedes's biggest Friday problem.

"It's more with the tyres, especially with the long runs they just completely went away on the rear," he added. "And also on the short runs, I'm not sure why.

"I just didn't get the most out of the tyres, the tyres are so complicated. It's a science to itself you just have to do your best to try and keep up."

Schumacher, who ended the day 11th fastest, also had a brake issue that curtailed his running early.

He thinks it is too soon to take an accurate reading on the competitive picture this weekend.

"Okay but I'm finding it difficult to see a picture of what is actually going on compared to the competitors, we need more time to analyse that to see who is going to be on what fuel and where we think we are.

"Tyres are very difficult. But it's the same for everyone."