The first iteration of the S197 has a lot going for it. Consisting of the 2005-2010 model years, these Mustangs are powerful and affordable options. The 3-valve 4.6 modular V8 in the GT sounds spectacular, is reliable, and easy to mod. The tried-and-true 4.0-liter V6 is no slouch either, and it’s also a breeze to upgrade.
These vehicles are less expensive now, but still have a great, retro-modern look. Though the 2010 Mustang did receive a visual update inside and out, the powertrain options were the same as the 2005-2009 models. It wasn’t until 2011 that the new engines were introduced.
Whether you want to autocross, track, or drag race, there are lots of different mods to consider. The same is true if you just want a fun daily driver. Whether you’re just getting started or are well into your S197 build, there’s something here for every enthusiast.
An exhaust upgrade should be one of the first things you add to an otherwise stock early S197. For owners of the V8 GT, a new exhaust will add a lot of sound and performance at a reasonable price. The 3-valve V8 has a distinct muscle car burble, which you can really optimize and bring to life with an aftermarket upgrade.
If you’ve got a V6 Mustang, an aftermarket exhaust can give it the acoustic output it deserves. You can even upgrade to a dual exhaust set-up, giving you enhanced power and sound, plus a new look.
Check out our full 2005-2010 Mustang exhaust guide for a detailed breakdown or if you need some help figuring out where to start. There are different kits for every need and price level, from axle-backs and cat-backs to headers and mid-pipes.
Early S197s have a lot of untapped potential when it comes to engine mods. Whether you’ve got the GT or V6, there are a ton of ways to increase your power levels under the hood.
Cold Air Intakes
Cold air intakes are a cost-effective and easy way to make more power. With a cold air intake, you’re letting more fresh air into your engine. There won’t be a massive horsepower increase, but more oxygen to burn means stronger performance from your engine.
The go-to bolt-on trifecta is a cold air intake and tune, along with a cat-back exhaust. Combine all three for a simple and relatively cost-effective way to take your Mustang to the next stage of performance.
When it comes to ease of installation and bang-for-your-buck, it doesn’t get much better than an electronic tune. By simply using a calibrator, you can customize your 05-10 S197’s engine to go beyond the restrictive factory settings.
ECU tuning is used by enthusiasts to calibrate the car’s computer with custom settings. This allows the engine to make more horsepower and/or torque. For your early S197, it’s a good way to bring it closer to the power levels of the later engines.
Whether used in conjunction with other bolt-ons or simply on their own, electronic tunes are one of the best ways to wake up your engine.
Though they require the most time, effort, and money to install, nothing will transform your engine like a supercharger. Adding one to your S197 Mustang is a big project, but it’s a must for those that want the maximum performance possible without swapping engines.
The forced induction that a supercharger offers can add hundreds of horsepower to your S197. Both the V6 and V8 of the 2011-2014 Mustangs offered about 100 hp more than their predecessors. Without a supercharger, the 2005-2010 models will be hard-pressed to reach that kind of output.
Although “handling” can be a vague term, it usually boils down to grip, cornering, body roll, and steering feel. Because Ford’s pony car didn’t get independent rear suspension until 2015, all of these can be greatly improved for Mustangs of this era.
Wheel and Tire Packages
Performance tires are vital for good handling, but sometimes get overlooked. If you’re serious about on-track performance, tires like Nitto’s NT55 G2 or INVO series offer tremendous grip. For those that daily drive their S197, a more typical set of all-season tires might make more sense.
A new set of lightweight wheels will complement your performance tires and can help you drop some unsprung weight. Get modern style wheels from the S550 or keep things classic. Check out our S197 wheel guide for an in-depth look at more options.
Because the suspension was updated in both 2010 and 2011, the 2005-2009 Mustangs need some aftermarket upgrades to feel as sporty. The 2010 is sharper than the previous years, but still needs upgraded springs to achieve the directness of the 2011+ models.
Consider lowering springs to improve your center of gravity and stance. In addition to giving your early S197 a sleek look, they’ll offer better rebound and less body roll than the factory springs. They’re affordable too, which makes them a popular first suspension upgrade.
If you want improved handling for the track, a set of performance shocks and struts will go a long way. Coilover kits are pricier, but will greatly sharpen your steering feel. They usually offer adjustable settings, letting you dial-in the exact rebound and stiffness you want.
Don’t forget that with great power comes the need for great braking capability. Performance pads and rotors are good to have on any build, but an absolute necessity if you’ve added lots of horsepower.
If you have an autocross-focused car, we’d stick with an affordable brake pad upgrade. Track or drag strip use will warrant upgrading both the pads and rotors for your Mustang.
The retromodern style of the 2005-2009 Mustang gives you a wide range of possibilities for style. Whether you want to take inspiration from the Bullitt, GT500, or go your own route, you can find aftermarket body components that will give you a new look.
Keep in mind that only the 2005-2009 model years share the same appearance mods. Ford updated the exterior and interior styling of the S197 in 2010, so these mods won’t be applicable for that model year.
Exterior and Body Appearance
From full body kits and hoods to headlights and spoilers, you can find hundreds of ways to optimize the street presence of your S197 Mustang. Even something as simple as adding a new grille can completely change the look of your car.
Adding new headlights can help modernize the older S197s. Their factory lights weren’t very bright to begin with and can get dimmer over time. An aftermarket pair adds style and makes your car safer in all conditions.
Body kits offer an entire change for your car’s appearance. Or you can add piecemeal elements like a front chin spoiler or rear diffuser for your own custom aesthetic.
Interior Parts and Accessories
The clutch pedal feel is arguably one of the least enjoyable driving elements of the S197 Mustang. Heavy in weight, and not especially linear in engagement, it can be a chore to operate. This is especially true for shorter drivers (or those who just completed leg day at the gym). An Accelatec Clutch Pedal Extension is an ultra-affordable remedy to this problem.
Beyond that, there are hundreds of ways you can protect your cabin, add some style, or increase practicality. Seat covers and floor mats might be a necessity depending on what type of climate you live in. And something as simple as a custom shift knob can really enhance the overall look of your interior.
Finding the Best Mods for Your S197
Upgrading your early S197 is part of the fun of owning one. Whether you’re focused on style or making the ultimate drag machine, the 2005-2010 platform is a good starting point. With these Mustangs, you don’t have to spend a lot of money to get awesome performance.
For those with a 2011-2014 Mustang, the refreshed iteration of the S197 has even more to offer. The new engine line-up and revised suspension, plus new styling, make it an appealing used car choice.
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This article was researched, written, edited, and reviewed following the steps outlined in our editorial process. Learn more about CJ's editorial standards and guidelines.