The words “Ford Mustang” are synonymous with the words “muscle car.” Even people who know little to nothing about cars can recognize a Mustang and know that they are a force to be reckoned with. That’s just how powerful the Mustang legacy truly is.
While the Mustang has been around for over a half-century at this point, only in the last decade has the Mustang become a car that you can realistically drive day-to-day. It is tricky to convert a thoroughbred muscle car into a daily driver without sucking the soul out of it. The mid-2000s S197 chassis Mustang didn’t bother with any daily-driver nonsense. It was designed with one thing in mind: the drag strip. Many enthusiasts argue that is the Mustang’s domain. That is what a Mustang is supposed to be for.
But the S197 has a problem: the newer sixth-generation S550 Mustang. 2005, the S197’s first production year, is almost 20 years in the past by this point and it reflects in almost every way with the S197. The S550, released in 2015, brings the Mustang formula into the 21st century, for real this time.
Both the S197 and S550 chassis are pureblooded Mustangs, the S550 with better usability. Deciding between the two boils down to a few key factors. In this comparison guide, we’ll discuss the primary differences between S197 and S550 chassis Mustangs and weigh the pros and cons.
S197 vs S550 Mustang Styling
As the saying goes, you never get a second chance at a first impression. While that saying is typically used in a different context, it certainly applies to cars too. While both S197 and S550 Mustangs are impressive to look at, they strike the eye in very different ways. The styling differences between the S197 and S550 Mustangs are far more significant than a simple change in the body lines. The chassis are fundamentally different at their core.
S197 Exterior Styling
As a kid, one of the first posters that I ever purchased was of an S197 Mustang. I don’t think that I was unique in that sense. In fact, the bulging hood scoop and foglight-brandishing grille of the S197 captured the imagination of an entire generation of kids growing up in the 2000s. For that reason, there is a certain nostalgia built into the S197s styling when looking back at it today.
It isn’t just childhood nostalgia either, as the S197 borrowed quite a few styling cues from the classics. The fastback reminiscent triple rear tail lights harken back to a time before sat-nav and MP3. From almost every angle you can see the old-school pedigree.
Just because the S197 design has a distinctive mid-2000s feel doesn’t mean that it isn’t a good-looking car. Beauty is in the eye of the beholder, and many people think that the S197 is the best-looking modern chassis to come from Ford.
The S197 styling continued to evolve through its impressive 10-year run, with a significant facelift occurring in 2010. The post-facelift S197 is noticeably more modern in design philosophy, yet also noticeably less sharp. It’s clear that the designer received instruction to soften some of the harsher edges of the S197 design, featuring a new headlight design with integrated turn signals, a new slimmer side mirror design, a prominent “power dome” hood, and revised three-lens tail lights with LEDs that blink in sequence for turn indication.
S550 Exterior Styling
It’s impossible to argue that the S550 Mustang doesn’t look mean. In fact, it’s easy to argue that it looks meaner than it actually is. If the S197 was meant to be a love letter to the Mustangs of old, the S550 in comparison is meant to be a testament to what Ford sees in their future. While boxiness was the defining feature of the S197’s aesthetics, wind-tunnel aerodynamics are the key influence in the S550’s design philosophy.
The S550’s thin headlights and gaping trapezoidal grille are stylishly nightmarish. Mustang enthusiasts have dubbed the new front facia the “shark bite” design due to the predator-like aggression. While the S550 lacks a lot of the vintage styling of the S197, it is clear that the Mustang legacy lives on in subtle ways.
Like the S197, the S550 continues the tradition of the split triple tail lights first found on 1960s Mustangs. The S550 also features a pronounced power dome and gaping side inlets on higher trim models. While it might look straight out of the 22nd century, the S550 is still a pony at heart.
S197 vs S550 Mustang Interior Styling
As with any car, the look of the interior is extremely important as that’s where you’ll be spending most of your time. As far as S197 vs S550 interior styling is concerned, much of what was said about the external styling of both chassis applies here as well.
S197 Interior Styling
When stepping inside an S197 Mustang, it is immediately apparent that the car is from the mid-2000s. While that might not be such a bad thing from the outside, it is rather unfortunate looking on the inside. As with most other Fords of the period, the S197’s interior is almost entirely plastic-clad. The unfortunate side effect of that is that everything feels cheap and rattly.
That also means that most S197s that you’ll find nowadays won’t have held up very well after 15 years of use and abuse. Scratches and blemishes are run-of-the-mill on almost any S197 available today.
The S197’s standard interior features might have been passable for 2005, but by today’s standards, they are rather grim. Ultimately, power windows and locks, a CD player, and power windows are all you can expect. Navigation, dual-zone climate control, and a backup camera came as options on 2010+ models, but that’s as far as technology went for the S197.
The only real saving grace for the S197’s interior is the retro nods to previous Mustangs that Ford threw in. The central speedometer and tachometer look straight out of a 60’s fastback with recessed faces and a retro font. The climate control vents are chrome, adding a bit of vintage flair.
S550 Interior Styling
With the S550, Ford stepped up their interior game in an unprecedented way. Unlike the S197, the S550 is a nice place to be for much longer than just a quick trip down the drag strip. Beyond just coming equipped with leather seats as standard, everything in the S550s cabin has a premium feel.
Where every panel in the S197 felt like it was one wrong nudge away from crumbling to bits, the interior in the S550 has a quality tactile feel. Yes, everything is still made of plastic. However, the rubberized feel of most of the S550’s interior bits is smooth and well placed.
The S550 has a massive leg up when it comes to onboard technology too. Unlike the S197, the S550 goes beyond basic interior necessities for a more luxurious experience. The S550 comes with an infotainment screen with Ford’s SYNC user interface, allowing for Bluetooth connectivity, navigation, diagnostic features, and optional Apple CarPlay. In 2018, analog cluster gauges were swapped for customizable digital ones, furthering the premium feel.
Safety was another priority for Ford with the S550, which is apparent with many of the optional high-tech safety features that they offered. To name a few, the S550 comes equipped with a rearview camera, pre-collision assist with automatic braking, and automatic lane assist. If you spring for a couple of options, you can have adaptive cruise control, remote start, and a heated steering wheel.
In many ways, the S550 ditched any muscle car impracticality in favor of luxury. That certainly shines through in the interior.
S197 vs S550 Mustang Engine Availability
It wouldn’t be a conversation about Mustangs if we didn’t talk about engines. When it comes to S197 and S550 powerhouses, there is some overlap and quite a few divergences. Many of the discrepancies between the available engines in both cars stem from Ford’s developed engine technology in the past ten years. As a result, there are some engines that Ford only offered in the S197, only offered in the S550, and a few that they offered in both. Here’s what that looks like:
|Engine||Horsepower||Torque||Years Available||Chassis Availability|
|4.0L V6||210hp at 5,300 RPM||240lb-ft at 3,500 RPM||2005-2010||S197|
|4.6L V8||300hp at 5,750 RPM||320lb-ft at 4,500 RPM||2005-2009||S197|
|5.4L V8 (Supercharged)||500hp at 6,000 RPM||480lb-ft at 4,500 RPM||2007-2009||S197|
|4.6L V8||315hp at 6,000 RPM||325lb-ft at 4,250 RPM||2010||S197|
|5.4L V8 (Supercharged)||540hp at 6,000 RPM||510lb-ft at 4,800 RPM||2010||S197|
|3.7L V6||305hp at 6,500 RPM||280lb-ft at 4,250 RPM||2011-2017||S197 & S550|
|5.0L V8||412hp at 6,500 RPM||390lb-ft at 4,250 RPM||2011-2012||S197|
|5.4L V8 (Supercharged)||550hp at 6,200 RPM||510lb-ft at 4,250 RPM||2011-2012||S197|
|5.0L V8 (302)||444hp at 7,500 RPM||380lb-ft at 4,250 RPM||2012-2013||S197|
|5.0L V8||420hp at 6,500 RPM||390lb-ft at 4,250 RPM||2013-2018||S197 & S550|
|5.8L V8 (Supercharged)||662hp at 6,250 RPM||631lb-ft at 4,000 RPM||2013-2014||S197|
|2.3L EcoBoost I4||310hp at 5,500 RPM||320lb-ft at 3,000 RPM||2015-2018||S550|
|5.2L Voodoo V8||526hp at 7,500 RPM||429lb-ft at 4,750 RPM||2014-Current||S550|
|2.3L EcoBoost I4||310hp at 5,500 RPM||350lb-ft at 3,000 RPM||2018-Current||S550|
|5.0L V8||460hp at 7,000 RPM||420lb-ft at 4,250 RPM||2018-Current||S550|
So, clearly, there wasn’t a shortage of engine options for either the S197 or the S550. While the S550 has lacked the same variety of choices that the S197 had so far in its production run, the S550 is still comparatively young in its production cycle.
S197 Engine Choices
When it comes to S197 engine choices, there were two primary options. You could get an S197 with either a V6 or a V8. Naturally, with environmental restrictions being far less in the mid-2000s, there was a much wider range of V8 options available. However, V6 powered S197s were still passable in terms of their output and torque.
Initially, in 2010, the only V6 option available for the S197 was the 4.0L Cologne V6. While a sturdy engine, it is extremely antiquated, having been in production since 1965. I guess you could say that it truly rounded out the S197’s retro attitude. It was the S197’s least powerful engine option with a frankly pathetic 210hp output.
The more modern 3.7L Cyclone V6 was by far the superior V6 engine option which was available in both the S197 and the S550. The naturally aspirated 3.7L Cyclone was the last of its kind offered in a Mustang to this day. The Cyclone was discontinued in 2017 in favor of the more efficient EcoBoost inline-4.
While there were only two V6 options available in the S197, V8 availability was a different story. Prior to 2011, the S197 was available with Ford’s Modular series of V8 engines. The Modular V8 series was Ford’s jack of all trades engine in the 2000s, powering everything from the Mustang to the Crown Victoria. In 2010, this meant a 4.6L Modular V8 which produced 315hp in the S197. A 5.4L version of the Modular V8 was strapped with a supercharger for the 2010 GT500 which produced 500hp.
Ford unveiled their new generation of V8 engines in 2011 with the “Coyote” designation. Since then, there have been three different versions of the Coyote V8, each with slightly more horsepower and torque. Only the first two generations were available in the S197, with Gen-3 Coyotes reserved for the S550.
S550 Engine Choices
When it comes to the engine options in the S550, Ford stripped the choices back a bit. While there might not be the same variety of engine choices, the choices that do remain don’t really leave any unfilled gaps.
The 3.7L Cyclone V6 and the 5.0L Coyote V8 are the only engines that overlap both platforms. Ford discontinued all V6 engines from the Mustang platform in 2017, meaning that the Cyclone V6 was only available for the first two years of the S550’s production.
The S550’s truly unique engine options come in the form of Ford’s newly developed EcoBoost engines. The 2.3L EcoBoost 4-cylinder debuted with the S550 chassis and was Ford’s answer to a high-performance, low emission motor to meet increasingly strict emission standards. In many ways, the 2.3L EcoBoost picked up where the 3.7L Cyclone left off. With a 310hp output, the 2.3L was not only more efficient than the Cyclone but also more powerful. Enthusiasts tend to enjoy the EcoBoost for its tuning potential as well.
For those looking for a true-to-form Mustang experience, the S550 is also available with a third-generation Coyote V8 in GT spec. With an output of 460hp, the 5.0L V8 delivers the performance that you’d expect from a pony.
To round out the S550 line, the GT500 model is available with a 5.2L Voodoo V8, also a part of Ford’s Coyote lineup. Pumping out 520hp, the 5.2L Voodoo is the top-of-the-line V8 that Ford offers at the moment.
S197 vs S550 Transmission Options
In the same way that there were multiple engine options in both S197 and S550 chassis, there were also a couple of options when it came to putting the power down. As the S197 and S550 chassis developed and received different updates, a primary source of change was through transmission options.
Both the S197 and S550 were/are available with both automatic and manual transmission options. With that being said, Ford encountered some growing pains while developing transmissions for both chassis.
S197 Transmission Options
Upon the S197’s release in 2005, manual transmission options came as standard. Naturally, as different engines required different transmissions, the S197 had three distinctly different manual transmissions available depending on the spec of the car.
One option was the Ford T5 transmission that could be found in V6-equipped S197 Mustangs. The T5 is perhaps the most notorious Ford transmission of all time, and one of the longest in production. Ford used the T5 in everything from the Astro Van to the Mustang. With a production run spanning 30 years, the T5 is a tried and tested 5-Speed transmission.
Ford opted for the TR-3650 5-Speed transmission for 2005-2010 Mustang GTs on the S197 chassis. The TR-3650 is a notoriously strong transmission, as it needs to be. With early-model S197 GTs rated at 300hp, the TR-3650 is said to be able to withstand nearly twice that amount of power without issue.
With the introduction of the Coyote V8 in 2011, Ford worked in collaboration with famous transmission production company Getrag to produce a novel transmission for the new S197 GT. Despite being a seemingly failproof collaboration, the resulting MT-82 5-Speed has significant issues. The MT-82 is notorious for being difficult to shift, often resulting in missed or jerky shifts. These issues were later solved for later model S550 chassis Mustangs.
Many enthusiasts that are unhappy with the MT-82 transmission found in S197 GTs opt to swap their transmission for much more popular TR-3160 and TR-6060 5-speed transmissions found in Shelby S197s.
The only automatic option for the S197 range is the 5R55S, which was available from 2005 to 2010. Generally, the overall reception of the 5R55S is pretty good, with many reports that they are reliable and unproblematic overall.
S550 Transmission Options
As far as S550 transmissions are concerned, the options are very similar to the S197 overall, with quality improvements made and more automatic transmission options available.
The S550 still utilizes the MT-82 transmission found in Coyote-equipped S197s. However, with many concerns about the transmission arising over the first couple of years of its implementation, key changes were made to make it better. The MT-82’s shifter bushing and bracket were changed on early S550 cars.
In 2018 and newer S550 Mustangs, the MT-82 received a serious refresh. This mainly included an adjustment to the gear ratios and new synchros. This largely fixed any issues that the early MT-82 faced, allowing it to live on.
The S550 chassis also introduced a few new automatic transmissions fit for use with EcoBoost engines. These included the newer 6R80 6-speed automatic and 10-speed 10R80 automatic. The 6R80 was available from 2011 to 2017, while production of the 10R80 began in 2018 and continues to the current S550s.
S197 vs S550 Mustang Handling
One of the most pronounced differences between the S197 and S550 chassis is Ford’s move towards emphasizing performance handling. With the S197, it is clear that Ford developed the mid-2000s chassis with early Mustang ideology in mind. Prior to the S550, the Mustang formula was straight-line-speed-centric, with little regard to handling characteristics.
With the S550, it is clear that Ford reversed their ideology. The S550 features some dramatic changes to the Mustang approach, with advanced suspension and balancing technology. The result is a Mustang that is fast in more ways than solely in a straight line.
S197 vs S550 Mustang Rear Suspension
The much-needed upgrade that transformed the S550’s handing characteristics the most is the inclusion of independent rear suspension. While most manufacturers updated to IRS in the late 90s and early 2000s, Ford delayed the update for far too long with the Mustang.
When reviewing the S197 GT500, Top Gear’s Richard Hammond stated that the Mustang was great in every conceivable way, except for a factor that matters a great deal: the handling. At the end of the day, the S197’s solid rear axle made it handle like a barge in a hurricane.
The antiquated technology didn’t allow for the rear wheels to move with the suspension independently, which led to a harsh ride over road imperfections and massive body roll around corners. Ford kept the 1920s design around as it was cheap to manufacture and better for drag racing. With the new chassis, they realized that those were no longer valid excuses.
The S550 was unveiled with independent rear suspension to the relief of every enthusiast under the sun. Independent rear suspension is not only more comfortable during daily driving, but better for performance driving. Eliminating body roll always leads to an improvement in handling. That is exactly the case with the S550.
S197 vs S550 Mustang MagneRide
The S550 chassis also saw some other 21st-century suspension upgrades that set it apart dramatically from the S197. One of those features is MagneRide. While still an optional feature on lower-trim S550 cars, it is a worthy investment for a few reasons.
For many enthusiasts, performance suspension is a nightmare if you intend on driving your car on any other surface than a racetrack. MagneRide suspension bridges the gap between performance and comfort suspension with the flip of a switch.
As can be inferred from the name, MagneRide suspension takes advantage of magnets and magnetorheological fluid to create an adjustable responsive damper. Essentially, MagneRide works by introducing conductive fluid to a magnetic current. When a magnetic current isn’t present the fluid within the shocks is less viscous, making the ride comfortable. When introduced to a current, the fluid stiffens, creating a fibrous fluid structure in the shocks. This is best for track or performance applications where a stiffer ride provides better cornering ability.
While MagneRide is a $1,650 option on lower-trim S550s, it is one of the best features to check off on the add-ons list. MagneRide is a must-have for those looking to daily drive their S550 during the week and have some fun on the track during the weekend. As it isn’t available on the S197 chassis, it should be a stand-out differentiator between the two chassis for those with track days in mind.
Other S197 vs S550 Mustang Performance Considerations
Beyond just suspension, transmission, and engine differences, there are a few other performance considerations to keep in mind when deciding between S197 and S550 chassis. Few Mustang owners are content with keeping their vehicle in stock form, so aftermarket support is important to keep in mind.
S197 vs S550 Aftermarket Support
Regardless of the chassis, Mustangs are muscle cars at heart. With that being said, aftermarket upgrades and performance add-ons have always been a staple of the muscle car community. In this respect, it must be said that the S197 has far more aftermarket support currently, as the aftermarket community has had much more time to develop performance parts for the older chassis.
Whether it be performance bolt-ons, tunes, supercharger kits, exhaust upgrades, or suspension refresh kits, the S197 unquestionably has more options to choose from. Since the S197 has been around for over 15 years now, tuning and performance part companies have had far more time to fiddle with the S197 chassis. Manufacturers like Roush, SCT, BBK, Steeda, and Edelbrock have a massive catalog of performance parts available for the S197, so it’s unlikely that there are any performance modifications out there that you couldn’t find parts for.
While there might not be the same breadth of options available for modifying an S550 yet, there certainly will be in the near future. Even though the S550 aftermarket catalog isn’t quite as big as that of the S197, there is still huge support. Many of the same bolt-ons, tuning, or suspension mods that can be found for the S197 are also available for the S550. There are just fewer options to choose from. As the S550 has been met with huge acclaim so far, the catalog will continue to grow.
S197 vs S550 – Why Choose The S197?
While it is pretty universally agreed that the S197 is the inferior chassis, it is in many ways the better Mustang. That might sound a bit confusing, but let me explain. Mustangs of decades prior have never given a crap about interior luxuries or comfort. Straight-line speed has always been the mantra of the Mustang, and that mantra lived on in the S197.
Even though the interior might fall apart around you and fast cornering was simply not an option in the S197, it would always go like a bat out of hell on the drag strip. That really is the S197’s bread and butter. And that isn’t a secret. Everyone knows those things about an S197.
For that reason, if you are simply looking for a fast drag car with pedigree, the S197 is the car for you. The fixed rear axle is far superior to the S550’s IRS for off-the-line digs. The insane amount of aftermarket support for the S197 is centered around making them have faster quarter-mile times.
Beyond performance, the S197 has become an icon of the Mustang line. The retro-futuristic design is a favorite among the community and brings nostalgia to those that grew up with a poster of one on their wall. If price is a factor, the S197 wins out too. Most driver quality S197 GTs go for less than $15,000 nowadays, where you’d expect to pay double for a comparable S550.
S197 vs S550 – Why Choose The S550?
Where the S197’s wheelhouse is straight-line speed and vintage charisma, the S550 is a far better all-rounder. Unlike the S197, the S550 is fast on the drag strip and your local Grand Prix track. Even better, the S550 will do a 10-second quarter-mile and get you to work comfortably.
Unlike the S197, the S550 is a Mustang that you can live with every day. With features like Bluetooth, heated seats, adaptive cruise control, and MagneRide suspension, the S550 is just as capable as a Honda Civic for daily driving duties. It corners, handles, and rides exponentially better than the S197, making it the best Mustang yet.
While aftermarket support might not be as all-inclusive as it is with the S197, there are still plenty of go-fast-bits that can be installed on the S550 chassis. Aftermarket support will only continue to get better as the S550 ages.
With S550 GT-spec Mustangs starting at $38,000, it is a significantly bigger hit to the wallet compared to an S197. However, it can be argued that the S550 is twice, if not three times, the car that the S197 is. For that price, you get a car that can do the racing and the road-tripping, whereas the S197 can only do the racing.
If you found this article helpful, check out some of our other Mustang-related guides. If you’re torn between a Coyote and EcoBoost Mustang, check out our Ford Mustang GT vs Mustang EcoBoost article for some guidance. As always, safe driving!