Pirelli prototype tires tested by Ferrari's Sainz and Leclerc

Formula 1 tire supplier Pirelli have been experimenting with low profile rubber this week, as the Ferrari drivers ran around Jerez for a total of 85 laps with 18-inch slicks.

Currently Formula 1 teams use 15-inch wheels with high profile tires but organisers have long mooted a move to bigger wheels and more modern looking rubber. Carlos Sainz and Charles Leclerc will be looking to get a feel for the future of F1 tires.

Cynics have long held that the main reason Grand Prix cars run tires with big sidewalls is to show the supplier's logos much larger. Nowadays performance road cars are rarely seen with such small diameter wheels.

Pirelli tire tests cause controversy

Pirelli tests have been the subject of controversy in recent years. In 2015, Mercedes were punished for running an unauthorized test on experimental rubber for Pirelli. The team were banned from a later Formula 1 test session and reprimanded after Lewis Hamilton and Nico Rosberg put 1000 kilometers on a range of rubber that Pirelli were planning to introduce the following season.

There will be no such reprimand for Ferrari for this test as the team had the seal of approval to take part. No doubt other teams will be keen to get their own hands on the experimental Pirelli tires before the rule change.

Bigger wheels and lower profile Pirelli tires will be a part of the 2022 rules package, originally planned for 2021 but delayed due to the coronavirus pandemic. The new wheels will be part of a sweeping overhaul of regulations specifying the dimensions of various components from the front wing to the rear.

The regulation changes should be comparable to those in 2009 and 1998, both of which significantly shook up the order and saw new world champions crowned. Reigning world champion Lewis Hamilton is yet to decide whether to continue his F1 career beyond the next regulation change.