S550 Mustang: 2015–2023 Guide
The S550 Mustang is the sixth-generation Ford Mustang, sold for the 2015 to 2023 model years. It’s the one that finally got independent rear suspension, went global and gave us the GT350 and the 760-hp GT500. Here’s what changed year to year, what to watch for, and how safe it really is.
S550 Mustang at a Glance
Model years 2015–2023 Nine model years
Platform S550 Sixth-generation Mustang
Production start 28 August 2014 Flat Rock, Michigan
Refresh 2018 New nose, no V6, 10-speed auto
Power range 300–760 hp V6 to Shelby GT500
Markets 120+ countries First right-hand-drive Mustang
What Made the S550 Mustang Different
For 50 years, a regular Mustang rode on a live rear axle. It was tough and cheap, but it also made the car skittish over bumps. The S550 Mustang finally changed that with an integral-link independent rear suspension, plus aluminum rear knuckles to cut unsprung weight. The chassis also got about 28% stiffer than the S197’s, so the whole car feels more planted.
The other big story was the world map. Ford designed the S550 to be built in left- or right-hand drive from day one, so the Mustang went on sale in more than 120 countries, including the UK, Australia and Japan. Every one of them came from Flat Rock, Michigan.
Under the hood, every launch engine made at least 300 hp, a first for the Mustang. That included a brand-new 2.3-liter EcoBoost turbo four, which was the first time Ford used that engine in a rear-drive car or paired it with a manual.
- 300+ hpEvery launch engine
- 28%Stiffer chassis
- 120+Countries
- 760 hpShelby GT500
What we like
- Independent rear suspension on every car
- Strong, sweet-sounding Coyote V8
- Huge aftermarket and parts support
What to watch
- MT82 manual gearbox complaints
- Weak crash scores outside North America
- Tight back seat, as in every Mustang
S550 Mustang Engines and Power
The S550 Mustang offered more engines than any Mustang before it, so the year you pick matters. A six-speed manual was available all the way through. However, the six-speed automatic was replaced by a 10-speed, co-developed with GM, from 2018, while the GT500 used its own seven-speed dual-clutch from Tremec.
| Engine | Years | Found in | Output |
|---|---|---|---|
| 3.7L V6 | 2015–2017 | V6 (base) | 300 hp / 280 lb-ft |
| 2.3L EcoBoost turbo I4 | 2015–2017 | EcoBoost | 310 hp / 320 lb-ft |
| 2.3L EcoBoost turbo I4 | 2018–2023 | EcoBoost (now base) | 310 hp / 350 lb-ft |
| 5.0L Coyote V8 | 2015–2017 | GT | 435 hp / 400 lb-ft |
| 5.0L Coyote V8 | 2018–2023 | GT | 460 hp / 420 lb-ft |
| 5.0L Coyote V8 (uprated) | 2019–2023 | Bullitt, Mach 1 | 480 hp / 420 lb-ft |
| 5.2L flat-plane-crank V8 | 2016–2020 | Shelby GT350, GT350R | 526 hp |
| 5.2L supercharged V8 | 2020–2022 | Shelby GT500 | 760 hp / 625 lb-ft |
Mid-cycle refresh · 2018
2015–2017 vs 2018–2023: What the Refresh Changed
The 2018 refresh didn’t touch the chassis, but it changed almost everything you see, hear and feel. Up front, the nose dropped about an inch and the grille got wider, partly because early cars drew complaints that they looked too much like a Ford Fusion.
The bigger news was under the hood. Ford dropped the V6 entirely, so the EcoBoost became the base engine and picked up more torque. Meanwhile, the GT’s V8 gained port and direct injection plus a 7,500-rpm redline, which pushed it from 435 to 460 hp. The old six-speed automatic also gave way to a quicker-shifting 10-speed.
Inside, you could now get a 12-inch digital gauge cluster with Normal, Sport and Track views, along with Apple CarPlay, Android Auto and Pre-Collision Assist. In Europe, Ford made automatic emergency braking and lane-keeping standard, which mattered a lot for its crash rating (more on that below).
Our verdict: if your budget stretches, buy a 2018 or newer. You get more power, the better automatic and the extra safety tech for not much more money.
A 2017 EcoBoost, before the refresh. Compare its taller nose with the 2019 GT at the top of this page.
- +25 hpGT V8
- +30 lb-ftEcoBoost
- 10Auto gears
- 12 inDigital cluster
S550 Special Models
The S550 Mustang had some of the best special editions Ford has ever built. There was also the 2019–2020 Bullitt, a tribute to Steve McQueen’s movie car with the same 480-hp V8 the Mach 1 later used.
2016–2020
Shelby GT350 and GT350R
526 hp Flat-plane V8 Manual only
A high-revving 5.2-liter flat-plane-crank V8 and a Tremec six-speed made this the driver’s Mustang. Ford ended production in late 2020 to make room for the Mach 1.
2020–2022
Shelby GT500
760 hp Supercharged V8 7-speed DCT
The S550’s top dog, with 760 hp and 625 lb-ft from a supercharged 5.2-liter V8, plus MagneRide dampers and huge brakes. It was the most powerful street-legal Ford of its day.
2021–2023
Mach 1
480 hp 5.0 V8 Manual or 10-speed
The first Mach 1 in 17 years borrowed the intake and oil system from the GT350, plus suspension and cooling parts from both Shelbys. Think of it as the track-ready GT.
S550 Mustang Recalls
Recalls aren’t exciting, but they’re the first thing to check on any used car. The S550 Mustang has had a fair number, especially early 2015 cars, which NHTSA lists with 11 recalls on their own. Below are the notable ones. Recall work is free at a Ford dealer no matter how old the car is or how many owners it’s had.
| Model years | NHTSA no. | What’s affected |
|---|---|---|
| 2015–2017 | 25V614000 | Water and road salt can corrode the front seat belt pretensioner cables, so a belt may not hold you properly in a crash. Announced September 2025. |
| 2015–2017 | 16V779000 | Engine oil cooler tube. Dealers replace the tube assembly. |
| 2015 | 16V643000, 20V331000 | Door latches. Dealers fit improved latches. |
| 2015 | 22V011000 | Brake and clutch pedal bumpers. Dealers replace both. |
| 2020 | 20V575000 | Rearview camera. |
| 2020–2023 | 23V727000 | The brake fluid level sensor may not light the warning lamp when fluid is low. |
| 2022–2023 | 23V070000 | Automatic transmission (a recall shared with other Ford models). |
| 2022–2023 | 24V493000, 25V096000 | The secondary steering torque sensor may be miscalibrated, so the wheel can turn side to side on its own. The second campaign covers cars fixed incorrectly the first time. |
S550 Mustang Safety Ratings by Region
Here’s where the S550 Mustang gets interesting. The same car scored very differently around the world, because each program tests and weighs things its own way. US tests focus on crash protection, while Euro NCAP and ANCAP also score rear-seat safety, child protection and driver-assist tech, and that’s where early cars fell short.
| Region | Program | Rating | What it means |
|---|---|---|---|
| United States | NHTSA | ★★★★★ | Five stars overall for the coupe (2016 and 2019 tested). Convertibles were only rated for rollover. |
| United States | IIHS | Good / Acceptable | Good in four of five crash tests in 2016, but Acceptable in the driver-side small overlap test, so it missed Top Safety Pick. |
| Canada | NHTSA and IIHS | As above | Canada doesn’t run its own crash-star program, so Canadian buyers use the US results. |
| Europe | Euro NCAP | ★★★ (from July 2017) | Two stars in January 2017. Later cars with standard AEB, lane-keeping and a fixed driver airbag were re-rated at three stars. |
| Australia and New Zealand | ANCAP | ★★★ (from Dec 2017 builds) | Two stars in January 2017, mostly because of missing driver-assist tech and rear-seat protection. Fastbacks built from December 2017 got the added tech and were re-rated at three stars; convertibles stay unrated. |
| Other regions | — | Not rated | We couldn’t find a published S550 rating from Latin NCAP, C-NCAP or JNCAP. |
Why two stars in Europe? Euro NCAP found the driver’s head hit the steering wheel because the airbag deflated too fast, and the rear passenger slid under the belt because there were no rear pretensioners. Ford fixed the airbag and added safety tech for cars built from July 2017, which lifted adult, pedestrian and safety-assist scores, though the crash structure itself was unchanged.
Buying a Used S550 Mustang
The S550 Mustang is widely seen as the best bang for your buck of any Mustang generation, and it’s easy to see why. That said, a few problems come up again and again in owner reports, so know what to look for.
- MT82 manual gearbox. The most common complaint: grinding into second or third when cold, notchy shifts and, in bad cases, worn synchros. Drive it cold if you can.
- Rear suspension clunks. Some cars knock over bumps or when pulling away, usually from worn bushings in the independent rear end.
- 10-speed automatic manners. Some 2018-and-up cars shift harshly or hunt for gears. A software update often helps, so ask for the service history.
- Coyote tick. A light ticking at idle is common on the V8 and usually harmless, but a loud knock isn’t.
- Early-car extras. On 2015–2017 cars, make sure the oil cooler tube recall is done, and check that the air conditioning blows cold.
Our picks
- Best overall: 2018–2023 GT
- Best on a budget: 2018+ EcoBoost
- Best for track days: Mach 1 or GT350
Think twice
- Heavily modified cars with no records
- Open recalls the seller won’t explain
- A V6 that isn’t priced well below an EcoBoost
Other Mustang Generations
The S550 sits between the retro S197 and today’s S650. Jump to the one before or after it, or go back to all seven.
S550 Mustang FAQ
What years are the S550 Mustang?
The S550 Mustang covers the 2015 through 2023 model years. Production started at Flat Rock, Michigan, in August 2014, and the seventh-generation S650 replaced it for 2024.
What’s the difference between a 2015–2017 and a 2018–2023 Mustang?
The 2018 refresh brought a lower nose, dropped the V6, raised the GT to 460 hp, swapped the six-speed automatic for a 10-speed and added an available 12-inch digital cluster. The chassis stayed the same.
Is the S550 Mustang reliable?
Mostly, yes, and Consumer Reports rated the 2015 model about average for its year. However, the MT82 manual gearbox draws the most complaints, and early cars had more recalls, so a well-documented 2018-or-newer car is the safer bet.
Why did the Mustang get two stars from Euro NCAP?
The early European car lacked automatic emergency braking and lane-keeping, its driver airbag deflated too fast, and the rear seats had no belt pretensioners. Cars built from July 2017 got the missing tech and an airbag fix, so they were re-rated at three stars.
Which S550 Mustang is the fastest?
The 2020–2022 Shelby GT500, by a wide margin. Its supercharged 5.2-liter V8 makes 760 hp, and it sends that through a seven-speed dual-clutch transmission.
Was the S550 Mustang sold in right-hand drive?
Yes. The S550 was the first Mustang Ford built in right-hand drive at the factory, so it was sold new in markets such as the UK, Australia, South Africa and Japan.
Sources
- NHTSA recalls database
- ANCAP: Ford Mustang rating, January 2017
- Autocar: Euro NCAP re-rating to three stars
- IIHS muscle car crash tests, 2016
- 2019 Mustang NHTSA and IIHS results
- Consumer Reports: 2015 Mustang reliability and recalls
- SlashGear: what S550 means
- 2018 Mustang GT: 460 hp and the 10-speed
- Ford Authority: GT500 ends after 2022
- Motor1: GT350 discontinued
Keep Exploring
See every Mustang generation side by side, or head back to the full Ford lineup.
Photo credits
- Header image: Vauxford, CC BY-SA 4.0, cropped and resized.
- 2017 Ford Mustang EcoBoost 2.3, pre-facelift S550,…: Vauxford, CC BY-SA 4.0, cropped and resized.
- 2016 Ford Shelby GT350 at the 2015…: Mustang Joe, CC0, cropped and resized.
- 2020 Ford Mustang Shelby GT500 in Oxford…: Ethan Llamas, CC BY-SA 4.0, cropped and resized.
- Ford Mustang Mach 1, S550 generation, on…: Alexander Migl, CC BY-SA 4.0, cropped and resized.