Also the biggest gap between pole position and the second. I only guess that gap is greatest at long circuits like the old Nurbergring but if anyone has statistics for various circuits I would find it most iteresting.
The one I immediately thought of was the 1968 Belgian GP - Chris Amon's pole lap was done in 3:28.6, while second fastest qualifying lap was Stewart's 3:32.3 - that's a gap of 3.7 seconds (incidentally Ickx filled the last slot on the front row with a time of 3:34.3, while 3:35 was enough for the second row)
This was the race where Amon's Ferrari 312 sported an aerofoil for the first time - goes a some way to explain why he managed to beat his team-mate Ickx by nearly six seconds....
Also in 1968 Ickx bounced back at the Nurburgring, taking pole in 9:04.0 with runner-up Amon a full ten seconds behind at 9:14.9. Mind you, this was the wettest GP at the Nurburgring since WW II....
The longest circuit didn't produce the biggest gap between pole position and second fastest - at Pescara back in 1957 Fangio was on pole - 9:44.6 - from Moss (9:54.7).
I can't think of any bigger gap, at least in an F1 world championship GP, but perhaps there is a proportionally larger gap somewhere?