One of the challenges Pirelli will have faced when designing the new 18-inch tyres was making sure that the grooved Intermediates and Wets had enough grip and longevity to safely get the drivers through rain periods.
Both Sebastian Vettel and Jos Verstappen, however, have criticised the job the Italian tyre manufacturer has done in designing the extreme Wets.
The Monaco Grand Prix got underway after an hour-long delay following torrential rain in the Principality, and it was around the lap 15 mark that drivers began transitioning from the Wets to the Inters as the track started to dry up.
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Vettel said the Wets were so hard in Monaco that they gave him very little grip, and he even went as far as to say that they were a “useless” compound to be on.
“As soon as you can go on the intermediate, you do it,” he said, quoted by Motorsport-Magazin.com.
“The rain tyres are far too hard for this track and even for Imola they were too hard.
“In rainy weather, we know that the current cars have a lot of aquaplaning. Pirelli hasn’t worked on this subject for years and everyone knows it. So we have to wait until it stops raining to be able to launch a race.
“I remember the days when we could have driven here in the rain, with no problem with this amount of water, but with these tyres it is impossible.
“Looking at them, the ‘extreme wet’ looks good but in fact they’re useless. As soon as you can switch to intermediate, you do it straight away.”
Isola, however, reveals that the tests conducted last season did not show a massive distinction between last year’s wet range and this season’s rain tyre.
“The Regen compound is different than the Intermediate, but it’s not much harder,” said the Italian, quoted by Planet F1.
“The tests we’ve done in the past showed (that the tyres) had similar characteristics to last year’s and we also wanted to keep the crossover time at a similar level as last year.”
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He does, however, concede that the crossover point varied in Monaco due to the nature of the track surface in Monaco, which naturally gives less grip than purpose-built racetracks.
“I think the crossover time here in Monaco between the wet tyre and the intermediate was quite different than at other tracks,” he explained.
“We tested the wets and inters in these conditions and even in cooler temperatures.
“It was mainly due to the type of asphalt. This is a real street circuit with street asphalt.
“The roughness is therefore much lower than with track asphalt and therefore much less grip is generated for the rain tyres.”
Vettel scored a point in Monaco after pulling off a strong series of overtakes on Zhou Guanyu, Daniel Ricciardo and Pierre Gasly.