Modified Ford Fiesta ST for Sale in the UK
The Ford Fiesta ST is one of the most popular hot hatch platforms in the UK. Lightweight, turbocharged and highly responsive to tuning, it has built a huge following among enthusiasts. Whether it's the Mk7 1.6 EcoBoost or the newer Mk8 1.5 three-cylinder turbo, modified Fiesta ST models regularly push well beyond stock performance figures. The Fiesta ST's compact dimensions and sharp chassis make it particularly rewarding on both road and track.
Stage 1 Fiesta ST builds often produce 220–240bhp from a simple ECU remap alone, representing a significant improvement over the standard 197bhp. Stage 2 builds incorporating upgraded intercoolers, performance intakes and sports exhausts commonly reach 250–270bhp. For those seeking more, hybrid turbo setups and stage 3 conversions on the Mk7 platform can exceed 280–300bhp with the right supporting modifications and fuelling upgrades.
The aftermarket for the Fiesta ST is extensive. Mountune — Ford's performance partner — offers a range of bolt-on performance packages that are insurer-friendly and retain full warranty compatibility. This makes the Fiesta ST one of the most accessible performance cars to modify responsibly. Suspension, braking and styling upgrades are equally well catered for, with numerous UK-based specialists supporting the platform.
On Madlows, you'll find enthusiast-owned modified Fiesta ST models for sale across the UK. Browse listings with full modification details, seller contact information and verified listing data. Whether you're looking for a lightly tuned daily driver or a fully built track weapon, the Madlows platform connects you with genuine sellers.
Modified Fiesta ST Listings
3 cars available
2016 Ford Fiesta T Ecoboost St 3
Stage 2, Tuned, Scorpion, Recaro, Intercooler
2015 Ford Fiesta T Ecoboost St 2
🔵 Airtec stage 3 intercooler, 🔵 Mapped by AJ motorsport at "stage3" at 350bhp, 🔵 BC racing coilovers (with upgraded top mount bearings as BC ones are terrible, 🔵 EBC big brake kit (330mm)
2019 Ford Fiesta T Ecoboost St 3
🔷X48R HYBRID TURBO, 🔷EIBACH LOWERING SPRINGS, 🔷MAXTON REAR DIFFUSER, 🔷 PUMASPEED SHORT SHIFTER
Popular Ford Fiesta ST Modifications
The Fiesta ST has one of the strongest tuning aftermarkets of any compact hot hatch. Below are the most popular upgrades found on modified Mk7 and Mk8 Fiesta ST models.
Engine & Powertrain
- • Stage 1 ECU remaps (220–240bhp)
- • Stage 2 with intercooler & intake (250–270bhp)
- • Hybrid turbo upgrades (280–300bhp+)
- • Mountune performance packages (MP215, MP235, MP280)
- • Intercooler upgrades (Mishimoto, Forge)
- • Performance intake systems
Chassis & Styling
- • Lowering springs and coilovers (KW, Eibach)
- • Big brake kit upgrades
- • ST Line and Mountune styling packs
- • Performance exhaust systems (Milltek, Scorpion)
- • Aftermarket alloy wheels
- • Splitters and body styling upgrades
Fiesta ST Buyer's Guide
When buying a modified Fiesta ST, these checks will help you assess the build quality and overall condition of the car.
Service History & Oil Change Frequency
Regular oil changes are critical on tuned Fiesta STs. Look for a full stamped service history with oil changes every 5,000–6,000 miles on cars that have been remapped or modified. The 1.6 EcoBoost is sensitive to oil quality; neglected oil changes can accelerate wear on the turbocharger and timing chain components.
Supporting Mods on High-Power Builds
On stage 2 and hybrid turbo builds, verify that appropriate supporting modifications are in place. An intercooler upgrade is essential at higher power levels to prevent heat soak. Check that the map has been written specifically for the turbo and supporting hardware fitted — mismatched tunes can cause detonation and engine damage.
Insurance and Declared Modifications
Ask the seller for a full list of modifications so you can accurately quote insurance before purchase. Undeclared modifications can void insurance policies. Mountune-supplied packages are often accepted by standard insurers; aftermarket remaps typically require specialist modified car insurance. Always confirm with your insurer before committing to a purchase.
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Frequently Asked Questions — Modified Ford Fiesta ST
How much power can a modified Fiesta ST make?
A stage 1 remapped Fiesta ST (Mk7 1.6 EcoBoost or Mk8 1.5 three-cylinder) typically produces 220–240bhp. Stage 2 builds with an upgraded intercooler, intake and exhaust commonly reach 250–270bhp. Hybrid turbo setups on the Mk7 can push beyond 280–300bhp with appropriate fuelling and supporting modifications. The Mk8 three-cylinder responds particularly well to tuning despite its smaller displacement.
Is the 1.6 EcoBoost reliable when tuned?
The 1.6 EcoBoost in the Mk7 Fiesta ST is generally regarded as a reliable engine when tuned to sensible power levels and properly maintained. Regular oil changes — every 5,000–6,000 miles on tuned cars — are essential. The engine can suffer from carbon buildup on the intake valves over time; walnut blasting is a recommended service item. On stage 2 and above, a quality intercooler is important to prevent heat soak and maintain reliability.
Are Fiesta ST modifications expensive to insure?
Insurance costs for modified Fiesta STs vary by insurer and the nature of the modifications. Performance modifications — particularly engine remaps and power increases — typically raise premiums. Specialist modified car insurers such as Adrian Flux, Footman James and Peter Best often provide more competitive quotes than standard insurers. Always declare all modifications accurately; failure to do so can invalidate a policy.