Ford Performance and Multimatic Motorsports announced the GT3 project in 2022, developing the car around the Dark Horse variant of the seventh-generation Mustang. The powertrain is a race-tuned 5.4-litre naturally aspirated Ford Coyote V8, developed in partnership with M-Sport, Ford's long-time World Rally Championship factory collaborator. The engine is managed by a Bosch MS 6.4 engine control unit and the transmission is a six-speed Xtrac sequential manual, positioned closer to the rear axle to improve weight distribution. Braking is handled by Alcon discs, and the suspension uses Multimatic five-way adjustable DSSV dampers with double wishbone geometry on both axles.
The chassis carries a fully integrated FIA-homologated roll cage. An early reliability issue saw the boot lid and rear diffuser prone to detaching at speed, causing significant disruption in the car's debut season. The Federation Internationale de l'Automobile granted Ford an erratum fix to address the problem, which Ford attributed to aerodynamic disturbance caused by closely following cars.
The initial customer teams were Proton Competition, running two cars in the FIA World Endurance Championship, and Multimatic Motorsports itself, entering two cars in the IMSA SportsCar Championship. The programme expanded significantly for 2025 with four additional teams — Dollahite Racing, Gradient Racing, Haupt Racing Team, and Riley Motorsports — fielding Mustangs in ADAC GT Masters, Deutsche Tourenwagen Masters, GT World Challenge, and Nürburgring Langstrecken-Serie competition.
The Mustang GT3's first season in 2024 was marked by the reliability teething problems before the erratum fix was implemented. Despite this, Proton Competition's number 55 car claimed the car's first pole position in the GTD class at the 2024 Michelin GT Challenge at VIR, while Multimatic Motorsports' number 64 car took the car's first podium in GTD Pro at the same event. Proton Competition also secured a podium at the 2024 24 Hours of Le Mans with their number 88 entry — Ford's first Le Mans podium since 2018.
The 2025 season delivered the programme's landmark result. The Mustang GT3 won the 2025 24 Hours of Daytona following a close battle with BMW and Chevrolet in the closing hours, marking the car's first victory at one of endurance racing's most prestigious events. Haupt Racing Team added a class win at the 2025 24 Hours of Nürburgring, finishing first in SP9 Pro-Am class and fourth overall.
Ford began testing the Evo upgrade package at a Daytona IMSA test in November 2025 and detailed the changes publicly in December 2025. The Evo addresses specific weaknesses in aerodynamics, vehicle dynamics, braking efficiency, and setup sensitivity, incorporating new dive planes, a revised front splitter and rear diffuser, an updated Brembo brake package, and improved suspension. The Evo made its race debut at the 2026 24 Hours of Daytona, with the original specification car making its final start one month later at the 2026 Bathurst 12 Hour before being retired from competition. The Evo version subsequently won at the 2026 Monterey SportsCar Championship at Laguna Seca.
The Ford Mustang GT3 marks Ford's first purpose-built Group GT3 programme using an American pony car platform, bringing one of motorsport's most iconic nameplates into the contemporary GT3 customer racing landscape. The car's first major outright victory came at the Daytona 24 Hours in its second full season, and the rapid expansion of the customer programme to six teams across four continents confirmed the Mustang GT3 as a commercially successful and competitively credible GT3 entry.