Pirelli's motorsport director Paul Hembery insists the wear rate of its soft tires is where it needs to be in order to force drivers to make two pit stops during races.
"The wear level is probably where it needs to be," Hembery said during testing at the Barcelona circuit on Friday. "If it's a two-stop strategy, you can't give them a tire that will last for 35 laps – otherwise that's a one-stop strategy.
"Where we would like to understand better is putting more rubber down onto the circuit. We also want to avoid having a dirty circuit where drivers can't move off line without pick-up," he added.
Pirelli has announced that it will take its hard and soft tires to the first four races of the season, hoping the gap between the compounds will help the show. The Italian manufacturer made some changes to its softer tires for the Barcelona test, and Hembery admitted he would like to be able to test in hotter conditions.
"There are changes from Jerez to here with the soft compound, which has evolved, intended to give us more durability, stability. We still have to see when we have some higher temperatures," he said. "We're suffering from testing here with some very cold temperatures and certainly at Jerez. For here we'll see in the analysis tonight, but we're not seeing the evolution of the circuit, the rubber being put down which will affect your wear rate between 30 and 40 percent between a Friday and a Sunday.
"That's something, strangely, we didn't see at Jerez and that's new for us. We've got some ideas about why that might be but we want to see the results from here to see if it's the same.
"We're also hoping to get some higher temperatures, say 25 degrees [77F] plus, on the track surface. The track is very cold, when it's eight degrees [46F] for most of the day it's almost a superficial track temperature and that's something we're trying to understand because we've tested, by and large, in higher temperatures. We're open to learning and we need to know how representative these conditions are."
Hembery also conceded Pirelli would want to be able to test its rain tires properly before the start of the season.
"If we could have a very good simulation of a wet race, that would be fantastic," he said. "We could do with a real downpour and then a drying track. That would be ideal because they could get out on the wets and go through the phases to the intermediates and back onto the slicks. That's what's needed for all the teams, to go from full rain through to dry, or the other way, then they can work out the change over points."
He also said he favored Paul Ricard as the venue for the final test of the winter if the Bahrain test is canceled due to the unrest in the country.
"If I had the chance to go to Paul Ricard and gain some wet testing with the teams, from a tire point of view that would be ideal. To come back here or to go to Jerez, it's cold, it's not going to give us any extra information. If not Paul Ricard, we'd prefer to go to Abu Dhabi where there's some heat.
"But there are a lot of question marks over what is going to happen over the next couple of weeks. It's going to be very difficult because the logistical demands on everyone are huge. So we all have to hope everything goes forward as planned, though that's currently a very difficult situation."