"The testing we have been able to do has been indispensable," he told reporters. "I'm not interested in what the others are doing, we are only concentrating on ourselves.
"The design of these new cars is very complicated, with a lot of aspects still to be defined," he continued. "Some parts of it we have already developed, whereas others still need working on to give their best. The run up to this season is a bit like a puzzle, with the parts slowing fitting together.
"It will be interesting to see how many cars will finish the first race in Australia," he added, a question that many are asking following the biggest single raft of rule changes in the sport's history.