Roush 421839 Single Adjustable Coilover Suspension Kit for 15-26 Mustang GT & V6

Vehicle Fitment

2015-2026 Ford Mustang GT 5.0L V8
2015-2026 Ford Mustang EcoBoost 2.3L Turbo
2015-2017 Ford Mustang V6 3.7L
2024-2026 Ford Mustang Dark Horse 5.0L V8

Fitment Notes

• Fits 2015-2025 Ford Mustang S550 and S650 platforms
• Compatible with GT, EcoBoost, V6, and Dark Horse models
• Fits both Fastback (coupe) and Convertible body styles
• NOT compatible with vehicles equipped with MagneRide suspension
• Direct bolt-on replacement for factory struts, shocks, and springs
• Professional installation recommended
• Wheel alignment required after installation
• Approximately 4 hours installation time

Features

• Single adjustable coilover design with height adjustment front and rear
• Pre-set 1.5" front drop and 1.0" rear drop as delivered
• Adjustable front ride height range: 0.8" to 1.5" drop from stock
• Adjustable rear ride height range: 1.0" to 2.0" drop from stock
• Rated for over 1.0g lateral skid pad acceleration
• Race-inspired design proven on track and autocross
• Pre-configured damping and spring rates for optimal balance
• Maintains excellent street ride quality while improving track performance
• Reduces body roll and improves cornering stability
• Allows corner weight adjustment for optimum balance
• Lowered center of gravity enhances handling dynamics
• Engineered and tested as complete integrated system
• Zinc plated steel construction with red powder coated springs

Specifications

• Brand: Roush Performance
• Part Number: 421839
• Product Type: Single Adjustable Coilover Suspension Kit
• Position: Front and Rear (Complete Kit)
• Adjustment Type: Single Adjustable (Height)
• Front Drop (As Delivered): 1.5"
• Rear Drop (As Delivered): 1.0"
• Front Adjustment Range: 0.8" - 1.5" drop
• Rear Adjustment Range: 1.0" - 2.0" drop
• Maximum Front Drop: Over 1.5" (with modification)
• Lateral Acceleration Rating: 1.0g+
• Front Strut Material: Zinc Plated Steel
• Spring Finish: Red Powder Coat
• Damping: Pre-Set/Fixed (Roush Tuned)
• UPC: 844764005037
• Country of Origin: USA
• Warranty: 1-Year Limited

Included Components

• Front zinc plated steel coilover strut assemblies with red powder coated springs (2)
• Rear Roush tuned shock absorbers (2)
• Rear adjustable spring mounts with red powder coated springs (2)
• Front height adjustment spanner wrenches (2)
• Rear height adjustment spanner wrenches (2)
• Installation hardware
• Installation instructions

Product Description

The Roush 421839 Single Adjustable Coilover Suspension Kit transforms your 2015-2025 Ford Mustang into a corner-carving machine with race-inspired handling that's equally at home on the street, track, or autocross course. This comprehensive suspension upgrade combines performance-tuned front coilover struts and rear shocks with height-adjustable springs, delivering a pre-set 1.5" front drop and 1.0" rear drop while providing the flexibility to dial in your preferred stance using the included spanner wrenches. Rated for over 1.0g of lateral skid pad acceleration, the kit dramatically reduces body roll and improves cornering stability while maintaining the comfortable ride quality Mustang owners expect for daily driving. Roush engineers developed and tested this suspension as an integrated system, balancing damping rates and spring rates to work harmoniously with the S550 and S650 chassis for proper front-to-rear weight transfer and neutral handling characteristics. The zinc plated steel construction ensures durability while the distinctive red powder coated springs add visual appeal under the fenders. Compatible with GT, EcoBoost, V6, and Dark Horse models (excluding MagneRide-equipped vehicles), this kit installs using factory mounting points in approximately 4 hours. Backed by Roush Performance's 1-year limited warranty and their reputation as a Ford OEM supplier since 1995.