McLaren sporting director Sam Michael thinks it is too early to judge whether Pirelli's 2013-spec tyres are easier to use, despite an encouraging first run in Brazil.
Formula 1's teams have been handed extra sets of 2013 rubber to try out for the first time at Interlagos. Pirelli is keen to ensure the new tyre is easier to get into the right temperature window than this year's products.
Early running in first practice showed the new rubber was able to quickly deliver performance, but Michael thinks it will need testing in much cooler conditions to be sure that the tyres are easier to manage.
The track temperature in Brazil nudged 50 degrees Centigrade on Friday, which is one of the highest experienced over the course of the campaign.
When asked by AUTOSPORT for McLaren's initial impression of the new tyres, Michael said: "Obviously the new ones have a little bit higher performance, so it is a faster tyre. Not by much, but definitely on our car it was a bit quicker.
"Our focus was on understanding different aspects of how it affects the rest of the car rather than lap times, so we had a lot of measuring equipment on board to take various displacement pressure measurements with those tyres.
"It was about data collection of the change rather than laptime, but we did think it was a bit quicker."
Michael reckons it will not be until the teams begin winter testing in cooler European temperatures that they will get a full picture on how the tyres are to work with.
"We have only tested in one temperature. So if it works better at other temperatures that are colder you wouldn't find that out until later.
"But it is Pirelli's job really to develop that side. Our job is to make sure it fits in well with other parts of the car, and the test went fine."