With just under two weeks before the opening pre-season test Pirelli's Paul Hembery says he is still expecting lap time improvements of around 5 seconds.
Speaking at an event in Turin to mark the company's 110th year in motorsport, Hembery admitted that he is as curious as anyone to see the results of the regulation changes for 2017.
Asked if he still believes lap times will improve by as much as five seconds, a prediction the Italian manufacturer was making last year, he said: "We were lucky to get the help of Ferrari, Red Bull and Mercedes, who each produced a hybrid (mule) vehicle, with 'skirts' like in the old days, and we ran a series of tests through the summer and now we're waiting for the 'real' cars which will be seen at the end of the month.
"I'm looking forward to seeing the design of the cars," he admitted, "because the look and feel of the cars will certainly be different, more aggressive. That's for sure.
"As for performance, as with the simulations, yes we're expecting five seconds, compared to Barcelona two years ago, so it's a big thing.
However, according to Hembery, it will be Melbourne when the effects of the numerous rule changes are really noticeable.
"The test car (used in 2016) was much slower compared to the actual car, it was a bit of a fake," he admitted. "Melbourne will really start showing the changes, the improvements.
"Despite the analysis and simulations we too are not really sure where we are with the tyres, which is the same for the teams. So it will be interesting for them too."