Alonso trails Vettel by thirteen points and must finish on the podium to stand a chance of winning a third crown.
"It was very hot out on the circuit today and, especially this afternoon, the track temperatures were well above normal, even for this circuit. We have not yet found the ideal balance on the car, so there is still a lot of work to be done with the engineers going into the rest of the weekend", he said.
"The predictions are for very different conditions from Saturday to Sunday, further reason to concentrate on the best choices when it comes to preparing the car for qualifying, but especially for the race. After so many Fridays, there is nothing much new to say about the tyres: the Hards appear to be more consistent, while the Mediums produce a quicker lap time"/
Alonso added that Ferrari must be ready for both dry and wet conditions.
"It’s hard to say if we prefer rain or the dry: as I said before, it is vital to be prepared to tackle both situations. We know we have to score 14 points more than Vettel for the Championship and not lose the same number to McLaren to maintain our second place in the Constructors’. Our targets are clear, but also difficult to achieve".