Has anyone ever been disqualified from a Grand Prix for being too slow? asked Graham Clayton via Facebook
There is usually a limit to how much slower a car can be than the others even to qualify - at the moment it's usually 107% of the pole-sitter's time, although this can be waived at the discretion of the stewards.
Therefore it's unlikely that a car which is very much slower could even start a race these days. But there does appear to be one unfortunate driver who was black-flagged for going too slowly: Al Pease, in his home Canadian GP in 1969.
Two years previously Pease, in a privately entered Eagle, had finished the race at Mosport Park - a circuit he had helped design - no fewer than 43 laps behind the winner, Jack Brabham, although most of that time was taken up when his battery went flat on the far side of the circuit, and he ran back to the pits to collect a new one and fitted it.
He entered the Canadian GP again in 1969, but what was essentially the same car was now rather outdated. Pease, who had been a successful sports-car driver in Canada but was now 47, said he realised he was struggling but tried to get out of the way - but the other drivers weren't so charitable.
After a couple of incidents, Pease blocked Jackie Stewart, whose team boss Ken Tyrrell protested to the stewards - and Pease was black-flagged after 22 laps.