What is the purpose of a rear diffuser?

A rear diffuser efficiently creates an increase downforce through a vacuum created by low pressure under the vehicle and high pressure behind the vehicle.

Kia Cerato GT Hatch Flow-Lock Rear Diffuser

Diffusers, Engineering basics

Model 3 Carbon Fiber Spoiler/ Blade ($229 w/ 20% OFF)

The Physics of Diffusers: How to Make a Car Really Suck –

Diffuser

2015-23 S550 Mustang EMP Aluminum Rear Diffuser –

BMW M2 M-Performance Carbon Fibre Rear Diffuser

2011 - 2014 Subaru WRX/STI Rear Diffuser (Sedan Only

2022-2023 Kia Stinger - M&S Force Series Rear Diffuser V2 – K8

AVR Jaguar F-Pace Rear Diffuser(V2) Fits All 2.0 LTR Petrol And Diesel