The legendary carmaker has still yet to confirm an exact time, but with Porsche's mighty 918 Spyder handing in a heroic 6m57s run, fans and rivals are understandably eager to know just what the P1 managed.
Rumours online have pointed to a 6m47s time, but according to the UK's Autocar, the truth might actually be in the vicinity of six minutes and thirty seconds. Not bang-on, but near enough to claim a comfortable record.
What is the magazine's source? No names were named, but it claims a McLaren insider promised a time "a fair bit quicker" than the 6m47s rumour, reportedly "six minutes 30 something".
For now, the 6m57s time of Porsche's exotic 918 - and the 6m55s/6m48s times of the barely street-legal Radical SR8 and SR8 LM cars - remains the time to beat.
Officially, at least. And Ferrari's LaFerrari might like a crack at the record, too.