Daniel Ricciardo admitted that he wasn't happy with his Friday free practice runs on the ultrasoft tyres in Shanghai.
“Half of the morning and half of the afternoon were good," he said afterwards. "Generally with the harder compounds I was more comfortable.
"But the ultrasoft I struggled with on the qualifying run," he added. "I didn't find a good balance on that today.
"The ultrasoft is difficult. I just struggled to get more grip out of it.
"Once we put the ultrasoft on we didn’t have as much speed," he explained. "We used that tyre two times today and both times I wasn't happy with it.
"This morning and this afternoon we didn't really find much time with it," Ricciardo said. "We went two tenths quicker from the soft to that [even though] it's two compounds softer.
"We struggled to get one lap out of it," he continued. "I felt like after the first sector I had already killed the tyre. The lap time didn't really improve after the first three or four corners.
"We need to find a bit of time there and understand where we are losing," he said.
"I obviously know what doesn’t feel right in the car. But now we need to find the answers and change that for tomorrow."
Ricciardo's problems with the ultras might not even turn out to be that significant. Their short lifespan could mean teams avoid relying on them for Sunday's Chinese Grand Prix.
"I don't even know if we'll use the ultrasoft that much in the race, but we want to find a bit more laptime with it," he said.
Drivers who start in the top ten begin the race on the same tyres they run in the second round of qualifying, a fact not lost on Ricciardo's thinking,
"It's no secret that a few people are thinking of qualifying on the soft, it's not that bad a tyre around here.
"With the soft and the medium we're more competitive," he said. "We're looking better on those tyres. That might push us in a certain direction for the race.
"The long runs were much better and I’m confident we can find the speed. Overall, we aren’t looking too bad and I hope we can be in the fight with Ferrari and Mercedes."