Mercedes boss Toto Wolff isn't a fan of Formula 1's "rubbish" ground-effect cars.

Last year, F1 introduced bold new regulations, including the return of ground-effect aerodynamics for the first time in 40 years, in an effort to promote closer racing.

However, so far, Mercedes has struggled to maximise the performance of its cars, with last year's W13 particularly susceptible to porpoising, a phenomenon associated with ground-effect racing cars.

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And as Wolff watches rivals Red Bull streak off into the distance during races, he let his feelings about the current designs be known. 

“You have two cars sailing off into the sunset on merit and there is a 20-second gap,” he said via The Mirror.

“I wouldn’t know between Aston Martin and Ferrari and us who was quicker because you are stuck where you are stuck and that is pretty much it.

“You can see [Red Bull’s] car is barely moving, be it on straights or over bumps. Corner-through balance looks easy.

“You look at all the other onboards and the cars are tricky. Generally, ground-effect cars are rubbish cars – it is just who has the least rubbish is ahead.”

Wolff's criticism also came after what he dubbed a "boring" Azerbaijan Grand Prix, where drivers struggled to overtake despite a 2.2km long main straight.

But the Austrian wouldn't go as far as suggesting F1 should reconsider its current car design path.

“I think after a race weekend like this, we mustn’t talk it down overall and say, ‘that is the wrong direction and we need to change completely’,” the Mercedes boss explained.

“It is more about understanding why it wasn’t entertaining and revisit it, and you have two cars that are sailing off into the sunset on merit, then there’s a 22-second gap."