Lewis Hamilton declared himself baffled by the extent of Mercedes' tire struggles in the Spanish Grand Prix, as he plummeted from the front row to a lapped 12th.
Although Hamilton's teammate Nico Rosberg managed to salvage sixth place, Hamilton tumbled down the field.
"It was an experience that I don't really want to go through again," said Hamilton. "Today I was doing absolutely everything the same as I did in Bahrain. But I had no grip, I couldn't push, and if I did, the tire just went off immediately.
"I'm absolutely lost today. I don't know what went wrong."
Hamilton admitted he had expected Mercedes to have made more progress resolving its tire troubles since Bahrain.
"It seems others made a bigger step for this weekend than us," he said. "Even though we brought upgrades, we didn't make any progress with the degradation."