SPA-FRANCORCHAMPS, Belgium (AFP) - A disappointed Sebastian Vettel blamed himself on Friday (Aug 25) after struggling to match Ferrari team-mate Kimi Raikkonen and trailing in fifth in practice for this weekend's Belgian Grand Prix.

The 30-year-old German was nearly half a second slower than his main title rival Lewis Hamilton who topped the times for Mercedes ahead of his 200th Grand Prix start.

Raikkonen was second.

"I'm not happy with myself, not happy with the car, so I think we have a little bit to come," said the four-time former world champion who leads the title race ahead of Hamilton by 14 points.

"I wasn't doing the best job today. I didn't really find the rhythm the way I wanted to. I know I can go faster...

"In terms of the car, the grip is fine. We just need to find the right balance. Sliding a bit too much, in places, with the rear, washing out with the fronts.

"Stuff that we can influence, I can influence by driving differently. It should be fine..."

He added: "Obviously, Friday is always difficult to judge because on Saturday everybody seems to make a step.

"If we can make the same step, we can be close. Mercedes is still the favourite. We're here to give them a hard time.

"Whenever they went out, they had the possibility to go fast. It's a long track and it's not so easy to put everything together.

"They look very strong, no doubt. I think for us, for myself, I was not happy. I was a bit so-so. I did not really find the rhythm, especially on the short run.

"The long run was better. Overall I think the car is there to do the job to go fast. We just need to get it right on all fronts. I need to do my job and we'll be fine."