The rear diffuser improves underbody airflow and the area directly behind the RS. By improving the airflow in these regions around the vehicle, we are able to generate rear-end downforce and reduce overall drag on the vehicle. The rear diffuser is a great addition for both track enthusiasts looking for more grip around the track or daily drivers looking for a bit more stability on the highway with improved gas mileage.

The rear diffuser is part of our Ventus 1 package for the Focus RS.  The goal of the Ventus 1 kit was to improve its aerodynamic performance over the factory setup. The rear diffuser and front splitter were designed together to improve downforce and equal the aerodynamic balance of the factory RS. The side splitters help improve downforce and decrease spillage of air out from under the car which improves efficiency. All the parts in the Ventus 1 Package work well as a system to improve the aerodynamics of the Ford Focus RS.