Pirelli says laps times in 2021 will likely be on a par with last season's performance based on the tyre manufacturer's analysis of pre-season testing and despite this year's rule changes.
Teams have carried over their 2020 chassis into this season, as mandated by the FIA, but several key regulation tweaks aimed at reducing downforce levels have led to alterations to the cars' bargeboards, rear brake ducts and, more significantly, to this year's floors.
The floor now follows a tapered contour towards the rear while the various longitudinal and lateral slots that were visible last year on the element and which were used to increase downforce have been ruled out.
It was anticipated that the combination of aero changes would shave 10 per cent off downforce levels with a further speed reduction induced by Pirelli's more robust tyres.
But a comprehensive analysis by Pirelli following three days of testing in Bahrain suggests that teams are likely to gradually recover the amount of downforce lost by this year's rules.
"The difference compared to last year is very, very, very small," Isola explained.
"I’ve tried to make some calculation on the lap times compared to last year and that's why I'm telling you that, if we consider that probably the track was not in perfect condition, plus the reduction in downforce, and the fuel level, so considering fuel corrected lap times, I believe that we are not going to see a delta lap time or a difference in reduced performance compared to last year."
Max Verstappen's pace setting 1m28.960s lap achieved on Sunday would have positioned the Red Bull charger P11 on last year's grid in Bahrain. However, with teams using conservative engine modes in testing and not pushing their cars to the max, Red Bull's flyer suggests significant margin for improvement.
Isola's thorough analysis has led him to believe that teams have already clawed back half of the lost downforce, an estimate that didn't surprise the Pirelli man.
"I believe that compared to the original plan to have a downforce reduction in the range of 10 percent, the teams were working around the modifications and the current situation is probably a downforce reduction in the range of four to five percent," said Isola.
"I'm not surprised by the amount of downforce they have been able to recover even before the start of the season, because we know that they are very good in doing that."
Isola was also happy with Pirelli's more robust tyres which he says will cope with the additional aero loads that are likely to appear in the second half of the 2021 season.
"I'm also happy that we decided last year, together with the FIA, F1 and the teams to work in two parallel directions: one to reduce downforce on the cars and the other to find a [tyre] construction that is able to cope with the additional loads that are probably going to happen in the second part of the season," he added.
"So despite the difficult situation we had with COVID, we took the right decision and, working in parallel, we have now a product that is more robust and cars that are probably as fast as last year."