Pirelli has announced its new hypersoft Formula 1 tyre will feature at the Canadian Grand Prix, the first officially confirmed appearance of the softest tyre in its revised range.
The compound is also likely to be used two weeks before the Montreal event at the Monaco Grand Prix, although the formal selections for European races are made later than those for flyaway events.
The supersoft and ultrasoft will also be used in Canada, while Pirelli has named the medium, soft and supersoft as its three choices for the Spanish Grand Prix.
Due to deadlines imposed by the FIA to help Pirelli with the logistical challenge of producing and shipping tyres to the opening flyaway races, the choices for Australia, Bahrain, China and Azerbaijan were made some weeks ago - in some cases as early as December.
Pirelli was due to make its tyre selections for the Canadian Grand Prix, the next flyaway race on the calendar in June, earlier, but the FIA allowed the tyre supplier extra time and linked the Montreal deadline with that of the first European event in Spain - allowing data from testing last week and this week to be used to inform its choices.
"We have a deadline that is March 8 to select the compounds for Barcelona and Canada," explained Pirelli F1 boss Mario Isola.
"Canada was February 22, but we spoke to the FIA and the teams to postpone the deadline to March 8 together with Barcelona, in order to collect more data from this test, because with our logistics, it's possible to produce and ship the tyre in time."
By delaying the Montreal decision until well into the test programme, Pirelli and F1 teams were able to learn a lot more about the hypersoft.
The compound has performed well on Barcelona's new surface, but is still too soft to be considered for the Spanish Grand Prix weekend.
"The hypersoft hung on a lot better than we expected," said Renault technical director Nick Chester.
"We thought it might be a single-lap tyre but Nico [Hulkenberg] had three good push laps on it with cool laps in-between and was quickest on his last one.
"For Carlos [Sainz Jr] it wasn't quite the same: his best was a second push lap.
"Generally it was hanging on OK. It was a bit grained by the last lap but for a high energy track like here it was hanging on quite well."