The new tyres are the result of a year-long process to improve on the previous generation of wets introduced 12 months ago.

Several experimental tyre compounds were evaluated and put through testing at Bridgestone’s proving grounds in Texas, with IndyCar teams helping by supplying data on loads and speeds usually experienced during wet running on road and street courses.

“We optimised the tyre to better fit wet conditions,” said Dale Harrigle, chief engineer for Bridgestone Americas Motorsports and manager of race tyre development.

“The key feature of this new rain tyre is it’s a new tread compound.

“It will be a learning process for teams and drivers. The biggest challenge for us is the concrete [on parts of some circuits], which is smooth.”

The latest batch of IndyCar wets will also feature a silver sidewall, to make the tyre easier to identify for fans.

The tread pattern and and depth from the previous wet-tyre design have been retained for the new specification.