A Roush Phase 3 Mustang is a factory-modified Ford Mustang that leaves the assembly line with performance and appearance upgrades already installed
Roush Performance is a company that partners directly with Ford to modify Mustangs before they reach dealerships. A Phase 3 is the highest level of modification Roush offers on new Mustangs, meaning the car has undergone engine tuning, suspension work, exterior styling changes, and interior upgrades all as part of the original purchase. You buy it this way from a Ford dealer — it is not something you add later.
The Phase 3 sits above Roush's Phase 1 and Phase 2 options, which are less extensive. Because these modifications happen at the factory level, they are covered under Ford's warranty, and the car's title and paperwork reflect that it is a Roush vehicle from new. This matters for resale value and insurance purposes.
Key Takeaways
- Roush Phase 3 Mustangs come pre-modified from the factory with engine, suspension, and styling upgrades included in the purchase price.
- The engine receives a supercharger and tuning that increases horsepower significantly compared to a standard Mustang of the same year.
- Suspension, brakes, and wheels are upgraded to handle the added power and improve handling and stopping distance.
- You purchase a Phase 3 through a Ford dealership, and the modifications are covered under Ford's factory warranty.
- Phase 3 is the most extensive Roush modification level available on new Mustangs, with Phase 1 and Phase 2 offering fewer changes.
Engine modifications and horsepower gains
The core of a Phase 3 upgrade is a supercharger — a mechanical device bolted to the engine that forces more air into the cylinders, allowing more fuel to burn and producing more power. Roush pairs this with engine tuning that adjusts fuel injection, ignition timing, and other parameters to make the supercharger work safely and efficiently.
The horsepower increase depends on which Mustang generation and engine size you start with. A Phase 3 on a current-generation Mustang (2024 and newer) with the 5.0-liter V8 produces roughly 500 to 550 horsepower, compared to around 480 horsepower in the stock version. Older generations see different gains — a 2018–2023 Phase 3 produces around 480 to 520 horsepower depending on the model year. Roush publishes exact figures for each year, so check their website or the window sticker at the dealership for the specific car you are looking at.
The supercharger also increases torque, which is the twisting force the engine produces. This makes the car feel faster off the line and during acceleration, not just in top-end speed.
Suspension, brakes, and handling upgrades
A stock Mustang is built for everyday driving. A Phase 3 adds suspension components designed to handle the extra power without the car becoming unstable or unsafe. Roush typically installs stiffer springs, upgraded shock absorbers, and sometimes adjustable suspension arms that allow fine-tuning of the car's geometry.
Brakes are also upgraded because a more powerful engine means the car accelerates faster and needs to stop harder. Phase 3 Mustangs receive larger brake rotors and higher-performance brake pads that resist fading during repeated hard stops — important if you plan to track the car or drive it aggressively.
Wheels and tires are upgraded as well. Roush fits larger, lighter wheels wrapped in performance tires that provide better grip than the stock rubber. This improves cornering, acceleration, and braking performance.
Exterior styling and visual changes
A Phase 3 Mustang looks different from a stock model, which is intentional — the modifications signal what is under the hood. Roush adds a more aggressive front bumper with larger air intakes, a hood with vents or a scoop to feed air to the supercharger, and side skirts that give the car a wider stance.
The rear typically receives a new diffuser or splitter designed to improve aerodynamics at high speed. Badging on the exterior identifies it as a Roush vehicle. Some Phase 3 models also include a unique paint color or stripe package, though this varies by year and availability.
These changes are not purely cosmetic — the hood vents and air intakes serve the supercharger system, and the aerodynamic pieces help the car stay stable at speed. They also make it clear to other drivers that this is not a standard Mustang.
Interior upgrades and technology
Inside, Phase 3 Mustangs receive upgrades that range from cosmetic to functional. Roush typically installs unique seat trim, custom floor mats with Roush branding, and sometimes upgraded audio systems. Some Phase 3 models include a performance gauge package that displays real-time engine data like boost pressure and oil temperature.
The interior changes are less dramatic than the exterior and engine work, but they reinforce that this is a specially prepared vehicle. The gauges in particular are useful if you plan to drive the car hard, because they let you monitor engine health in real time.
Warranty coverage and ownership considerations
Because Roush modifications are done at the factory under Ford's supervision, they are covered by Ford's factory warranty. This is a major advantage over buying an aftermarket supercharger and having it installed at an independent shop — you have recourse if something fails, and the warranty does not disappear if you sell the car.
The warranty period and coverage terms are the same as a standard Mustang: typically three years or 36,000 miles for bumper-to-bumper coverage, and five years or 60,000 miles for powertrain. Some dealers offer extended warranties that cover Roush components specifically.
Insurance costs are higher for a Phase 3 than a stock Mustang because the car is more powerful and more expensive to repair. Contact your insurance company before buying to understand the premium difference. Resale value is generally strong because Roush vehicles have a following among enthusiasts, though you will not recover the full cost of the modifications if you sell the car later.
Phase 1, Phase 2, and Phase 3 compared
Roush offers three levels of modification on new Mustangs. Phase 1 is the most basic, typically including suspension upgrades, wheels, tires, and exterior styling changes, but no engine modifications. Phase 2 adds a supercharger and engine tuning to the Phase 1 package, producing less horsepower than Phase 3 because the supercharger is smaller or the tuning is more conservative.
Phase 3 is the full package: the largest supercharger, the most aggressive tuning, the most extensive suspension work, and the most dramatic exterior styling. It is also the most expensive. The price difference between phases varies by model year and dealer, so compare window stickers to see what you are paying for at each level.
If you want a modified Mustang but do not need maximum power, Phase 1 or Phase 2 may be enough and will cost less. If you want the most performance Roush offers on a new car, Phase 3 is the choice.
Frequently Asked Questions
Can I get a Roush Phase 3 on any Mustang model?
Roush Phase 3 packages are available on most current Mustang models, but not all. Availability depends on the generation and engine size — Roush typically offers Phase 3 on V8 models. Check with a Ford dealership or Roush's website to confirm whether the specific Mustang you want can be ordered with Phase 3 modifications.
Is a Roush Phase 3 faster than a stock Mustang?
Yes. The supercharger and tuning add 20 to 70 horsepower depending on the model year, which translates to faster acceleration and higher top speed. The suspension and brake upgrades also improve handling and stopping power, making the car faster in corners and during emergency stops.
Do I have to buy a Phase 3 from the factory, or can I add it later?
Roush modifications are designed to be installed at the factory before the car leaves Ford's assembly line. You order a Phase 3 through a Ford dealership as part of the original purchase. Aftermarket shops can install Roush parts later, but this voids the factory warranty and is not the same as a factory Phase 3.
What is the price difference between a stock Mustang and a Phase 3?
The cost varies by model year and dealer, but Phase 3 typically adds $10,000 to $15,000 to the base Mustang price. Get a quote from your dealership for the specific year and configuration you want, because pricing changes annually and may differ between dealers.
Will a Phase 3 Mustang use more fuel than a stock model?
Yes, generally. The supercharger and more aggressive tuning increase fuel consumption, especially if you drive the car hard. Exact fuel economy depends on driving habits — highway cruising will use less fuel than frequent acceleration, but a Phase 3 will not match a stock Mustang's efficiency in any scenario.