REVAMP YOUR MUSTANG'S STYLE WITH THE RTR REAR DIFFUSER!

The RTR Rear Diffuser is the ultimate enhancement for the rear end of your 2018-2023 Mustang! They fit all ‘18-’23 Mustang EcoBoost equipped with ActiveExhaust and all Mustang GT trim levels. The RTR Rear Diffuser isn’t a complete rear diffuser replacement, they were designed to seamlessly integrate with your OEM rear diffuser.

I know what you’re thinking; “Hey, that’s the formula for the Venturi effect!” If that’s not what you were thinking, don’t worry - you’re not alone.

Think of your car as a boat. Water runs quickly under the boat and pops out the back (with the pressure of the engines) in the form of a wake. Air does the same thing under your car. The formula above explains the speed of the air under the car that creates suction and produces more grip. It also helps us understand that we need to control the low-pressure area behind the car to maintain this suction. That’s where the rear diffuser plays a big role. In 1977, the Lotus F1 team wanted to increase traction on their car. They found it by studying airplanes…then flipping it upside down like Maverick in Top Gun. To help control the low-pressure area behind the car, the rear diffuser was created. It’s kind of like making sure the wake behind the boat is not too wild. By increasing downforce with minimal drag, the cars were faster through the corners.

Ford began using integrated rear diffusers on performance-based Mustang models in the early 2000’s. This became more evident on the S550 Mustang. Lindsay Ross, RTR Creative Director, saw this and enhanced it using his motorsport knowledge to make it more prominent and functional. Combine the RTR Rear Diffuser with the other aerodynamic components around the vehicle like the front RTR Chin Splitter, Rocker Splitters, and Quarter Splitters; Lindsay carried that Venturi effect throughout the Mustang.

That’s one of the best features of owning a serialized Mustang RTR. You get all of the benefits of our aerodynamics packages. If you do not own a serialized Mustang RTR, you can buy all of our RTR components and equip your Mustang with them to get the same benefits. Our focus has always been performance through balanced handling and keeping smiles on faces.

If you want to install the RTR Rear Diffuser on your 2018-2023 Mustang GT or EcoBoost, follow along below for a step by step installation guide. We'll show you what’s involved with the installation of the RTR Rear Diffuser. Let's get started!

How to Install RTR Rear Diffuser

Step 1: Gather Your Materials

Inside the box, you'll find:

• RTR Rear Diffuser
• (4) 5mm short screws
• (2) 5mm long screws
• (4) 5mm washers
• (2) Diffuser brackets
• Alcohol wipes
• Adhesion promoter
• Installation instructions

Step 2: Prepare Your Tools

For this installation, you'll need:

• Socket wrench
• 5mm socket
• 7mm socket
• Dremel (or reciprocating saw and file)
• Cutting wheel and sanding bit for Dremel

Step 3: Remove OEM Diffuser Fins

Using a low to medium speed, cut out the OEM fins. Start by cutting along the inside where the fin meets the valance. Then, cut along the length of the fin from the bottom to the top on each side. Finally, make the last cut across the top to remove the OEM fin. Don't forget to debur the edges of the cuts for a smooth, flat surface.

Step 4: Remove Valance Screws

Using a 7mm socket, remove the four screws at the bottom edge of the valance and set them aside. The outer screws will be reused.

Step 5: Install Brackets on RTR Rear Diffuser

Install the brackets onto the RTR Rear Diffuser using two 5mm short screws and washers. Hand-tighten the screws, leaving an air gap equal to or greater than the thickness of the valance.

Step 6: Prepare the Valance

Thoroughly clean the valance with a mild soap and water solution. Once clean, wipe it down fully with the alcohol pads, followed by the adhesive promoter.

Step 7: Attach the RTR Rear Diffuser

Slide the diffuser up from the bottom, capturing the rear valance with the bracket. Hold the adhesive surface away from the valance until properly aligned. Do not press the adhesive until the screws have been installed.

Step 8: Reinstall Valance Screws

Reinstall the OEM 7mm screws into the outside position near the exhaust tip. Install the 5mm long screw into the inner position towards the center line of the vehicle. Then, tighten the 5mm short screws inside the valance on the left and right sides of the vehicle. Be careful not to overtighten.

Step 9: Complete the Installation

Press the double-sided tape against the rear valance to complete the installation. Make sure everything is secure and properly aligned. Your Mustang is now Ready to Rock!

That's it for this installation guide of the RTR Rear Diffuser for 2018-2023 S550 Mustang. We offer several components for your S550 Mustang, feel free to check them out below.