Many may not understand what is "placebo effect". To put it layman's term, it's a feeling one will get after paying for some modification, bought a device, filled higher grade petrol, added addictive etc (& also partly because of the "extraordinary" claims in advertisements, sales talk, forum chat etc), to the point that one CANNOT believe what you paid for does not work as claimed even though there may not be noticeable difference in terms of performance from stock or standard settings/tuning. Phew...there...understand now? No? How about this...

Ah Beng found a performance chip in ebay which claims that after installing it, his car horsepower could increase by 30 ponies. A bargain Ah Beng thought at USD60 so Ah Beng bought and installed it. Wow, he said. The car feels smoother, more pickup, and definitely more power!! Ah Beng is happy. Weeks later, Ah Beng after much persuasion from his car kaki, did a dyno & found out his car actually has less horsepower than his friend's who did no modification or added anything at all! His friend drives the same car as Ah Beng. Ah Beng later recovered from his placebo effect.