SHANGHAI (Reuters) - McLaren endured another tough weekend in China on Sunday with both drivers failing to score points for the second race running and the team tumbling down the Formula One constructors' standings.
After a double retirement in Bahrain, the team's first since 2006, Jenson Button and Danish rookie Kevin Magnussen finished a distant and disappointing 11th and 13th respectively in Shanghai.
They had qualified 12th and 15th.
McLaren, the second most successful team in the sport, had led the constructors' championship after the opener in Australia when Magnussen was second and Button third but they slumped to fifth overall on Sunday.
"We're struggling to get front tyre temperature in the wet and it's also an issue in the dry," said Button, whose team have not won a race since 2012 and went through 2013 without appearing on the podium.
"It's not that you don't switch the tyre on so much, it's that it just grains immediately as soon as you put it on the car," added the 2009 champion.
"We've got a lot of work to do and it's tough for all of us, it's tough for us out there driving the car because we've got to put up with it for an hour and a half."
Magnussen said the car overall was good but lacked overall grip: "We just need loads of downforce," he said.
Racing director Eric Boullier said the team would use the three-week break between China and the first race of the European season in Spain to address the problems.
"Our car isn't competitive enough, we know that," said the Frenchman.
"We'll work flat-out between now and then (Barcelona) in an effort to address our car's shortcomings. We know what we have to do, and we'll work night and day to do it."
(Writing by Alan Baldwin in London, editing by Pritha Sarkar)