| ECU Calibration | Performance | $500–$1,500 | Higher engine output and sharper throttle response | Approximately 10–25% more power on turbocharged engines, depending on engine condition and fuel quality | May improve acceleration but can increase drivetrain stress and fuel consumption | Medium | Drivers seeking the largest power improvement per dollar |
| High-Flow Intercooler | Performance | $600–$1,400 | Reduces intake-air temperature and heat soak | More consistent power during repeated acceleration; power gains are usually modest without software changes | No direct comfort penalty; supports reliable turbocharged performance | Medium | Turbocharged cars used in warm climates, spirited driving, or track sessions |
| High-Flow Intake System | Performance | $250–$800 | Improves intake airflow and increases induction sound | Usually a small power increase, commonly around 2–8% when correctly matched to the engine | May introduce more engine noise; filtration quality is important | Low | Owners wanting a simple engine-bay upgrade and more audible turbo or intake sound |
| Cat-Back Exhaust System | Performance | $700–$2,000 | Improves exhaust sound and can reduce back pressure | Typically a small power increase, often around 1–5% on a standard engine | May add cabin drone or increase exterior noise; emissions compliance varies by location | Medium | Drivers prioritizing sound, appearance, and moderate performance refinement |
| Lowering Springs | Handling | $350–$900 | Reduces body roll and lowers the center of gravity | Typical ride-height reduction of approximately 20–35 mm | Sharper cornering response but a firmer ride and reduced ground clearance | Medium | Street drivers wanting a lower stance without full suspension replacement |
| Adjustable Coilover Suspension | Handling | $1,200–$3,500 | Allows adjustable ride height and, on many kits, damping control | Can significantly reduce body roll and improve cornering balance when correctly set up | Firmness depends on settings; poor adjustment can reduce grip and comfort | High | Enthusiasts who want adjustable street, mountain-road, or track settings |
| Performance Anti-Roll Bars | Handling | $400–$1,100 | Reduces lateral body movement during cornering | Provides a quicker steering feel and can alter understeer or oversteer balance | Limited comfort penalty when moderate settings are used; excessive stiffness can reduce grip on uneven roads | Medium | Drivers seeking flatter cornering without substantially lowering the car |
| Performance Tires | Handling | $600–$1,400 per set | Improves braking, cornering grip, and steering precision | Can reduce dry braking distance by several meters compared with worn or basic tires, depending on conditions | Often increases road noise and may reduce wet-weather or cold-weather performance if an extreme compound is chosen | Low | Nearly every driver; the most broadly effective handling upgrade |
| Upgraded Brake Pads and Fluid | Handling | $250–$900 | Improves pedal consistency and resistance to brake fade | Better repeated-stop performance; peak stopping distance still depends heavily on tire grip | May produce more dust or noise, especially with track-oriented pads | Low–Medium | Cars used on mountain roads, autocross courses, or track days |
| Lightweight Alloy Wheels | Handling / Styling | $900–$2,500 per set | Reduces unsprung and rotational mass while updating the exterior appearance | A weight reduction of approximately 1–3 kg per wheel is possible with carefully selected wheels | Can improve steering response and ride quality; oversized wheels may have the opposite effect | Low–Medium | Owners wanting a combined visual and dynamic improvement |
| Front Splitter and Rear Spoiler | Styling / Aerodynamics | $400–$2,000 | Creates a more aggressive appearance and may improve high-speed stability | Meaningful aerodynamic benefit requires correct design, balance, and sufficient vehicle speed | May reduce ground clearance and increase wind or road noise | Medium | Owners prioritizing appearance and occasional high-speed or track use |
| LED Exterior Lighting Upgrade | Styling | $150–$800 | Modernizes exterior lighting and can improve visibility | Light output improvement depends on beam pattern, housing design, and legal compliance | Little effect on handling or comfort; incorrect installations may cause glare or warning lights | Low–Medium | Drivers seeking a subtle appearance update and improved illumination |
| Sport Steering Wheel | Interior | $500–$1,800 | Improves grip, tactile feel, and cockpit appearance | No direct power or lap-time benefit; may improve driver control and comfort | Flat-bottom or thicker designs can improve legroom and grip, but airbag compatibility is essential | Medium–High | Drivers who value frequent hands-on interaction and interior personalization |
| Aluminum or Composite Pedal Set | Interior | $80–$300 | Provides a sportier appearance and more defined foot contact | No measurable engine or suspension performance gain | Minimal comfort effect; secure fit and correct pedal spacing are critical | Low | Owners wanting an inexpensive interior detail upgrade |
| Sound Deadening and Interior Insulation | Interior | $400–$1,500 | Reduces road, tire, and vibration noise | Cabin noise reduction commonly ranges from approximately 2–6 dB when applied correctly | Improves long-distance comfort but adds weight and installation time | Medium–High | Daily drivers and touring-focused owners |