I understand what CI means and i understand what fuel economy is but what i do not get is that some airlines change there sops and do screw up al other airlines it simply does not work! if some airlines fly at 250 at fl 250 other airlines fly faster and have to slow down and get above their descent path its very selfish to do this! i am sure a lot of guys do not get this but i do! And i fly 20 sectors a week in a 737 and i get tired by some clowns who fly 250 knots all the time its not gonna work at busy airports so if you hear planes are following you go to at least 280.