Track resurfacing has had a "big impact" while high temperatures "a bit of a worry"; Rain forecast for the weekend, however
Tuesday 25 November 2014 17:51, UK
Brazilian GP pacesetter Nico Rosberg was among those to suffer excessive tyre wear during Friday practice, when track temperatures at Interlagos nudged 57 degrees Celsius.
Rosberg currently stands 24 points behind Mercedes team-mate Lewis Hamilton in the title race and gave himself the best possible start to the weekend by setting the fastest time in both sessions.
However, the German said afterwards that he was also keeping an eye on his tyres – with a number of drivers reporting tyre graining and blistering as the medium and soft compounds struggled to cope in record conditions.
Pirelli has switched its tyre nomination from hard and medium compounds because the 4.309km layout is smoother this year after it was resurfaced.
“The unusual thing was with the asphalt being completely new it is very different to last year and that has a big impact on the car,” Rosberg told Sky Sports F1.
“Initially the balance was completely wrong and I had understeer and we made the front-end softer and the rear-end harder and that worked out and then I felt quite comfortable on one-lap. Then on the long-run we topped the car right up and did a lot of laps to practice for Sunday.
“It was extremely hot, I think historically they have never seen as hot asphalt temperatures as today on this track and so the tyres were completely blistering and that was a bit of a worry today so that is something we need to keep an eye on.”
Pirelli motorsport director Paul Hembery blamed the tyre graining on oil in the new tarmac and said the blistering was caused by the high temperatures.
Dark clouds descended by the end of the session, however, and with rain forecast for the weekend, it’s entirely likely the problems won’t repeat themselves.
“The track is very different from last year,” Hembery explained. “We’ve lost a lot of the macro-roughness, which is about 50 per cent than last year, so it’s a very smooth track and in the first sessions we saw a lot of oils coming out from the new tarmac that we’ve got out there, which you get in new surfaces, so a lot of graining going on the first run on the tyres in P1.
“It improved a little bit through the day having said that it’s a strong pull for something like the softer compound here, when we’re getting up to something like 60 degrees track [temperature] so a little bit of blistering we’ve started to see on the front tyres.
“But who knows what the rest of the weekend’s going to hold.”
