Three thousandths of a second
Last weekend in the Malaysian Grand Prix qualifying, practice or some such, two drivers completed the circuit in times three thousandths of a second apart. I have no idea which drivers, but apparently it was significant, and led to Eddie Jordan (I think) suggesting that it was the equivalent of the width of a matchstick.
Based on Jenson Button’s pole position time of 1m 35.181s and the circuit length of 5.543km, he covered an average of 17.5cm every 0.003 seconds. Matches are generally 50mm long by 2mm square. So that equates to a match 4.36m in length.
Maybe Eddie meant one of those huge, ornamental matches that you can hang on the wall.