F1: Raikkonen says more struggles ahead for Ferrari

Kimi Raikkonen says the Ferrari Formula 1 team is being compromised by its car's weakness in the slipstream of rivals.

Raikkonen started seventh on the Singapore Grand Prix grid last weekend after a software glitch spoiled his final run in qualifying, but rose to fifth in the early part of the Marina Bay F1 race before getting jumped by Felipe Massa's Williams during the first round of pit stops.

The Finn found it difficult to make progress from there and was stuck behind the sister Williams of fellow Finn Valtteri Bottas for most of the second part of the event, before slumping to eighth in the latter stages as the fresher-tyred cars of Jean-Eric Vergne and Sergio Perez overtook. Raikkonen said the Ferrari tends to lose too much rear downforce in the wake of other cars, which compromises the F14 T's ability to look after its tires.

"Most of the race I was stuck behind the Williams, mainly Massa and then in the end Bottas," Raikkonen explained. "I had a bit more speed than them but obviously you cannot get past.

"Running behind seems to affect us a lot. When you get close, you lose all the downforce and it just destroys your tires. First of all you cannot get close enough to try to attack, then you lose your tires. It's very disappointing.

"In race conditions it's very important to get clean runs. We've seen in the past that we have the speed, but when you get stuck behind somebody, the race is pretty much done."

Raikkonen said the prodigious straightline speed of the Williams cars had made his life even harder.

"It's hard to overtake. I got close to them a few times but coming out of the corners you just lose grip," he added. "If you don't get the proper jump on them you cannot pass them on the straight.

"It's a strong point of their car, and here where you only have two places to overtake, it's very hard to get past."