Pirelli's F1 boss does not disagree with drivers who are calling the full wet tyres "useless".

A Formula 1 rule dictates that if a race starts behind the safety car, as it did in the Saturday sprint at Spa Francorchamps, then the drivers must have full wets fitted.

But at Spa, almost the entire field made the decision to pit for more competitive intermediates as soon as the safety car peeled off.

"The full wets are pretty useless," Mercedes driver and Grand Prix Drivers' Association director George Russell said afterwards.

"It's really, really bad. Those tyres are probably six, seven seconds a lap slower than the intermediates.

"The only reason you'd ever want to use them is when you'd be aquaplaning on the inters, so that needs to be improved considerably."

Fascinatingly, Pirelli boss Mario Isola does not necessarily disagree with Russell.

He revealed at Spa that Pirelli is already brainstorming the idea of a 'super intermediate' or 'intermediate-plus' tyre for the future.

Isola said Pirelli has improved the performance of the full wets recently, but the big issue is that the race director appears increasingly reluctant to allow any racing action to take place when circuits are very wet.

"Are they just safety car tyres?" the Italian wondered. "We always look at the drivers' view of things and it's an issue we're working on with the teams and the FIA.

"If the idea is to keep looking for things that can reduce the tyre spray so that drivers can race with full wets, we should keep the two products (intermediates and full wets) that we have.

"But if the rain tyre can only be used behind the safety car, then that tire is useless. Then I agree with the drivers," Isola added.

"We have to decide which way we want to go and which product is needed for Formula 1." body check tags ::