Probably just psychological but if the pulley bearings were really bad they would make a bad noise and create extra load but you wouldn't think it would be enough to affect performance.
I think that unless we 'think' our car runs better after we play/spend money on it, we'd soon give up the game.
"If anyone disagrees with anything I say, I am quite prepared not only to retract it, but also to deny under oath that I ever said it." --T. Lehrer
"The secret of success is sincerity. Once you can fake that you've got it made." -- Jean Giraudoux