"We expected Mercedes to be very strong so tomorrow should be an interesting race", said Vettel.
After a "disappointing" start that saw him finish second, eighth and fourth in the first three races of the season, Hamilton got back to his winning ways at the Azerbaijan Grand Prix a couple of weeks ago.
Obviously we had the change for everyone but I think they are a bit harder so for me it was pretty straightforward as I said because I was happier with the vehicle with that tyre. Mercedes, on the other hand, have not challenged for the win, but were benefactors of a well times safety vehicle in Baku that allowed them to finish ahead of the Ferrari.
The top drivers barring Alonso were running on soft tyres from Q2, and hence, will start this Sunday's Spanish GP on the rubber. The Ferraris were clearly sandbagging, just because they could.
On the back of Hamilton's dominant pole position in the Australia season opener, Mercedes was beaten by Ferrari for three consecutive qualifying shoot-outs, as the Scuderia emerged with what appeared to be the 2018 field's quickest vehicle. This 74th career pole is a return to competitive form just when he needed it, having been outpaced over the single lap at Bahrain and China by his team-mate Bottas, and by Vettel in the last three races. And that's not sufficient enough to win a world championship. All the teams are well aware of the Circuit de Catalunya as it serves as the pre-season testing base.More news: Pochettino expects 'complicated' transfer window for Spurs
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"It was a great close qualifying, obviously all weekend was close", Hamilton said."Ferrari was probably sandbagging just because they could, they've always had a very quick vehicle".
"I think overall the tyres this weekend are different".
Commenting on his performance in qualifying Bottas said he felt good in the vehicle, and that his focus was on getting the maximum possible from the race. "'In 2009, the sport said 'let's go with less aerodynamics and better racing", but it didn't change too much.
"It was good to work the SuperSoft tyre a bit better today, it felt like a better tyre for us so we have made some good progress in that area". His team-mate Sergey Sirotkin was in 18th but has a three-place grid penalty from the last race. He said part of the problem is that many times "a lot of us drivers might agree but we know our teams won't agree". Does it make a difference?
"I mean we are drivers", said Vettel, "that's not to say that we know everything, we don't anything about engineering the auto but we know how the cars feel, how to drive the cars. But it's nice that whether you start first or sixth, you can fight for the win in terms of pure performance - which is good for people watching too because you don't know what will happen", he added.