Apr.12 (GMM) F1 drivers had one word on their lips after Friday's practice sessions in China -- 'tyres'.
"It was the worst tyre I've ever experienced," said Mercedes' Lewis Hamilton, who described the situation as 'hardcore'.
"There were bits flying off all over the place. It didn't last long," he added.
He is referring to the softer of the two compounds, while quick straight out of the box is being likened to the old 'qualifying' compounds of the past.
McLaren's Jenson Button agrees: "It's very tricky and I don't think you're going to see many quick laps in the race.
"It's extreme degradation and from a tyre that's doing a (one minute) 35 in qualifying spec and then in the race after eight laps doing 48 ... we're slower than GP2 cars."
Mark Webber, of Red Bull, said the soft tyre is "virtually impossible" to balance in terms of setting up the car.
"You slither around like you're in Formula Ford," he is quoted by Germany's Auto Motor und Sport.
Not everyone was unhappy. Lotus and Ferrari appear content with the soft tyre, and especially Brazilian Felipe Massa, whose engineer told him on the radio his pace is "not good but incredible".
"Felipe Massa certainly looked quick today," agreed Red Bull team boss Christian Horner.