Side Skirts, Splitters & Diffusers
Everything that happens below the rocker-panel line: that’s where you gain visual stance and the little aerodynamic advantage available without wind tunnels.
The three parts
The side skirt visually connects the two bumpers and lowers the line. The lip - or splitter - extends the front bumper close to the ground and reduces the amount of air passing underneath. The diffuser does the opposite at the rear: it lets the air rise gradually instead of separating abruptly.
Ground clearance decides
On a lowered car, and even more so with air ride, these parts scrape. A flexible polyurethane lip bends and springs back; a fiberglass one breaks at the first curb. Choose the material based on the car’s actual ride height, not the photo.
Mounting
A lip must be supported by struts to the hood or subframe, never by the bumper screws alone: at 100 km/h, the low pressure presses it against the ground and tears out the mounting points.
