2021 Ford Mustang
Sixth generation · S550 2015–2023
The S550, the first Mustang with independent rear suspension as standard, built 2015–2023.
The 2021 model year
Overview
The Mach 1 returned for the first time since 2004, slotting in as the GT's hard-edged track option and effectively replacing the departed Bullitt. It paired a 480 hp 5.0 V8 with cooling and aero borrowed from the GT350 and GT500 (oil, transmission and rear-axle coolers; a front splitter and rear spoiler), available with either a Tremec 6-speed manual or the 10-speed automatic. The GT500 continued at 760 hp.
Specifications
- Engines
-
- 2.3 L EcoBoost turbo I4 (base) 310 hp
- 2.3 L EcoBoost High Performance Package 330 hp
- 5.0 L "Coyote" V8 (GT) 460 hp
- 5.0 L V8 (Mach 1; returns) 480 hp
- 5.2 L supercharged "Predator" V8 (Shelby GT500) 760 hp
- Transmissions
- 6-speed manual (Mach 1: Tremec TR-3160), 10-speed automatic (10R80), Shelby GT500: 7-speed dual-clutch (Tremec TR-9070) only
- Body styles
- Fastback coupe, Convertible
- Base price
- $27,155 (EcoBoost fastback) ≈$31,400 today (inflation-adjusted) Original MSRP adjusted for inflation (CPI, 2024); not the car's current market/collector value. Source: U.S. Bureau of Labor Statistics, CPI-U (U.S. city average, all items), annual average.
- Production
- 52,414 (US)
Year over year
What changed
- The Mach 1 returned (first since 2004) as the GT's track-focused variant, replacing the Bullitt.
- Mach 1: 480 hp 5.0, GT350/GT500-derived cooling and aero; available with the Tremec 6-speed manual or 10-speed auto.
- GT350 / GT350R were gone; the GT500 (760 hp) continued.
Living with it
Reliability & ownership notes
- The Mach 1 adds dedicated oil, transmission and differential cooling versus a standard GT — a genuine durability benefit on track.
- Manual-equipped Mach 1s use the Tremec TR-3160 from the GT350, a step up from the standard MT82.
Worth knowing
Notable
- Mach 1 nameplate revival — a well-equipped, collectible GT-based track car.
- GT500 continued as the supercharged flagship.
Famous variants this year
Sources
Other Sixth generation years
Explore the S550 generation → All Sixth generation · S550 years →