Sebastian Vettel was 'pretty happy' after setting the pace on Friday in practice for Sunday's Abu Dhabi Grand Prix, although he insisted it was 'difficult' to say how they compare to their rivals.

Vettel was third fastest in the first session at the Yas Marina Circuit, before re-taking his customary top spot in FP2, his quickest effort a 1 minute 41.335 seconds, which saw him conclude the opening day 0.155 seconds up on his Red Bull team-mate, Mark Webber.

"It's difficult to say today how we compare to the others, we know the Lotus is quick here, but we also had decent pace today," said Vettel, who will be looking for his seventh win in a row on Sunday, after triumphing in India last weekend and claiming his fourth F1 Drivers' title.

"It's not always so easy at this circuit with the conditions changing throughout the day; we start in the sun and finish at night and the track temperature changes during that time. But [we had] no big issues, so I'm pretty happy."

Webber was similarly pleased, even if he did have to play second fiddle again to Vettel - as he has done for most of the year.

"The second session today was more representative of the race and qualifying than the first, due to the time of day and temperatures," explained the Aussie. "It was a lot about the tyres today; I think the soft tyre will hold out better here than it did last week.

"It wasn't a bad feeling for the first day, we got the information we needed, so let's see how we get on tomorrow.

"We will go through everything now tonight and really try to understand the car on both tyre compounds," Webber concluded.