Talk:NISSAN SILVIA (S15) R3 Spec Championship/@comment-26845160-20171206075133/@comment-193.133.132.2-20171206103538

Diffuser creates downforce. It does it by means of preassure change mainly at the back of car. In short you de-compress air as it travels underneath the car, thus creating suction. When car move forward it traps air underneath. At very end of diffuser air is rapidly expanding, creating very low preassure - this low preassure allows car to be "sucked" to the ground :) i.e. Just like syringe, when you block one end and try to pull cylinder up - it will suck your skin/finger inside by the same effect of low preassure. Hope this helps, but subject is much bigger.