Brazilian GP: Pirelli concerned about resurfaced track if it rains

With the opening day of action at Interlagos highlighting that the resurfaced asphalt is releasing a lot of oil, Pirelli has urged drivers to take 'great caution' if the expected rain arrives.

"With rain, when we got these oils coming out of the new bitumen - oil and water - you don't need to be an expert to know that that is not a great combination," explained Pirelli motorsport director Paul Hembery.

"So if it does rain we have to urge great caution. The racing line is different in the rain compared to the dry, so drivers will be going over parts of the track that were not run over today.

"That is a precautionary note that we have said - we have seen very high level of surface oil coming through."

BLISTERING NOT A BIG ISSUE

A number of teams experienced blistering of their tyres during Friday practice at Interlagos with the high temperatures punishing the rubber.

Hembery admitted that the matter had been a worry initially, but reckoned cooler temperatures and a more rubbered-in track surface would ease the situation.

"When we changed from hard to medium and medium to soft we said that the question mark we had about the softs here would be blistering in the extreme temperatures," he said.

"But looking at the history books it hasn't been this hot for 10 years. But lo and behold what do we get? The hottest temperature in 10 years.

"The first session was a bit more worrying, and we saw a lot of graining on all four tyres and thought this was going to be a tough weekend if it doesn't change or evolve. The second set that went on already lost the graining on the front tyres."

If the event remained dry, then Hembery reckoned the medium tyre would be the one used more during the race - with two stops expected.