Ford Mustang S550 (2015-2023) vs. S650 (2024+) What’s New, What’s Bett

The Ford Mustang has always been a symbol of American muscle, but the transition from the S550 (2015–2023) to the S650 (2024+) marks another generational leap forward in its history. Whether you’re a prospective buyer or an S550 owner wondering if it’s time to upgrade, here’s what you need to know about the key differences, standout features, and shared DNA between these two iconic pony cars.

Lets have a look at some "Headline Differences" between the S650 and S550

Design & Styling: A Modern Edge

S550: Classic Mustang cues with a retro-modern blend—aggressive front end, classic taillights, and a familiar silhouette.

S650: Sleeker, sharper, and more aerodynamic. The new model features a lower, wider stance, a redesigned front grille, "cut" rear deck with full-width LED taillights that scream next-gen muscle. The S650 also introduces new wheel designs and more aggressive body lines for a sportier look.

So the S650 made some aggressive exterior changes, but beauty is in the eye of the beholder....so its up to you whether you prefer the S550 gen 1 (2015-17) the facelift (2018-2023) - which featured the Bullitt and Mach 1 special editions; or the new S650, launched in 2024, which in turn offers the all new Dark Horse edition.

Below: Dark Horse emblem on glittering Blue Ember paint work

Performance: More Power, Better Handling

S550:

5.0L Coyote V8: ~450–460 hp (depending on the year and variant).

2.3L EcoBoost: ~310 hp.

6-Speed Auto or 10-speed automatic (2018+ models) or 6-speed manual. MT-82 (GT / Bullitt / Ecoboost) or Tremec (Mach 1)
MagneRide Suspension introduced as an option on 2018+ models and standard on Mach 1

S650:

5.0L Coyote V8: 460-465 hp (thanks to a new dual-air intake system (see pic below) and improved exhaust flow). The US offers a 500 hp output on the Dark Horse but EU models are reined in by emissions improving tuning. However this can be easily rectified with a Steeda intake and tune, pushing power well over 500hp.

2.3L EcoBoost: ~ No Longer Available in Europe

10-speed automatic or 6-speed manual. MT-82 (GT) or Tremec (Dark Horse)

MagneRide Suspension tuned (Optional on GT and standard on Dark Horse) for sharper handling and adaptive damping.
Front end suspension re-worked to improve handling

Massive increase in braking performance with huge boosted brakes, including all round 2 piece discs on the Dark Horse. Amongst the best production brakes on any current vehicle.

Dark Horse engine comes with forged internals for track pounding endurance, plus improved cooling for oil and transmission.

Below: Steeda Q767 Dark Horse showing off the factory Dual intakes of the improved Coyote.

Technology: A Digital Revolution

S550:

SYNC 3 infotainment (8-inch touchscreen, Apple CarPlay/Android Auto).

Analog instrument cluster (with optional digital elements in later 2018+models).

S650:

SYNC 4 with a 13.2-inch touchscreen (faster, more intuitive, and fully customizable).

Fully digital 12.4-inch instrument cluster (configurable layouts, including a track-focused mode). Very customisable dash including retro Fox Body style dash dials and more.

Ford’s BlueCruise 1.5 (hands-free highway driving) and advanced driver aids (lane-keeping, adaptive cruise control, and more). Down sides can be annoying "nanny" systems which keep telling you to put your hands on the wheel....even while your hands are on the wheel!

This is a big decider for some Mustang owners. Will you embrace the digital vibes of the new S650 or do you prefer the all analog look of the S550?

Below: Dark Horse interior showing acres of screen coverage! All fully customisable...

Interior: A Driver-Focused Cabin

S550: Comfortable but more traditional—physical buttons, a retro-inspired dashboard, and cloth/leather options.

S650: More premium and tech-forward.

Flat-bottom steering wheel (standard on most trims).

Recaro sports seating is an optional extra for both the S550 and S650 chassis

Ambient lighting and higher-quality materials (soft-touch plastics, aluminium accents).

Platform & Engineering: A step forward.

S550: introduced the revolutionary (for a Mustang) step forward to IRS (Independent Rear Suspension) based platform.

S650: A continuation of the S550 chassis with reworked front suspension geometry and components and totally overhauled braking system. Electronics totally overhauled.

Steeda Q Series Variants:

S550: The Q500 Enforcer was based on the GT, the Q767 Mach 1 was based on the Mach 1 (!) and the Q850 StreetFighter could be based on either. The Bullitt could be built into one of the Steeda Steve McQueen limited Edition Bullitts, if you were lucky enough to get one, otherwise it could just be a standard Q500 but based on a Bullitt.

S650: The Q500 Enforcer is based on the GT, with the Q767 Dark Horse now based on a Dark Horse (!). Again the Q850 StreetFighter could be based on either platform.

Conclusions: What we recommend...

So that is the major differences covered. What do we in Steeda Europe think of this?
In essence the S650 is a facelifted S550, sharing the same basic chassis and set up and engine but improved in many regards, especially with the braking performance which is a very large step forward over the S550.; and with the major changes aesthetically being the exterior and interior.

So for us, if all out performance is your aim, then the best Mustang currently out there on a track (not including the GTD) will be a Q767 Dark Horse. Its got the improved forged engine, aerodynamics and cooling upgrades and of course those fantastic brakes from the factory, plus it's combined with the legendary Steeda handling mods that turn it into a pure sports car able to hang with the best in the world and providing V8 thrills like literally no other car out there.

If performance ISN'T your focus then the options remain open! If you just want a cool Mustang, then the S550 or S650 might work for you based purely on your visual preferences; or indeed your interior analogue vs digital preferences. The Bullitt's highland green lustre might make the choice for you, or the aggressive looks of the Mach 1, especially when upgraded with the front and rear track pack splitter and spoiler.

In terms of how I look at the new S650 here is how I would decide.

1. I want a brand new Mustang, and I dont care about anything apart from it being new and a Mustang: Buy a GT

2. I want a brand new sports car for every day fun, but I really want driveability and dont care about going on track much (maybe a track day or two every year) : Buy a Steeda Q500 Enforcer

3. I really want a Dark Horse just because I think they look nice and are cool. Buy a Dark Horse

4. I want the best performing / top level Mustang i can get, or I am really keen on track days / Nürburgring etc: Buy a Steeda Q767 Dark Horse.

To enquire about a new Steeda Q Series Mustang contact Steeda UK,

Ford Mustang S550 (2015-2023) vs. S650 (2024+) What’s New, What’s Better, and Should You Upgrade?

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