The preloaded tunes (often called "canned tunes") that come with the SCT X4 for Ford vehicles are designed to work with stock or lightly modified cars (like those with a cold air intake). These tunes are specific to your engine type—gas or diesel—and are generally categorized by the fuel octane you plan to use or the task you're performing.1
1. Gas Vehicle Tunes (Mustang, F-150, Explorer)
For gasoline engines, the preloaded tunes are primarily based on octane levels. Higher octane allows the tuner to advance spark timing and adjust fueling for more power.
- 87 Octane: A "Performance/Economy" blend that provides a modest power bump and crisper throttle response while still allowing for cheap fuel.
- 91 Octane: A performance-oriented tune for mid-grade fuel.
- 93 Octane: The most aggressive preloaded tune, maximizing horsepower and torque gains (especially effective on Eco Boost and 5.0L Coyote engines).
2. Diesel Vehicle Tunes (Power Stroke)
Diesel tunes are categorized by how you intend to use the truck. They offer significantly higher gains than gas tunes (sometimes over $100$ hp and $200$ lb-ft of torque).
- Performance: The highest power level; intended for "street" use or racing. Not recommended for towing.
- Street: A balanced tune with moderate power gains, safe for light towing (usually under 5,000 lbs).
- Towing: Optimized for pulling heavy loads. It focuses on transmission shift points and EGT (Exhaust Gas Temperature) management rather than peak horsepower.
- Transmission Only: Keeps engine power at stock levels but improves shift firmness and timing—ideal for heavy-duty hauling where you want to protect the transmission.
Key Adjustable Parameters
Beyond the power files, the SCT X4 allows you to manually adjust specific vehicle settings without needing a custom tune:
- Speed Limiter: Raise or remove the factory top-speed governor.
- Axle Ratio: Correct your speedometer if you’ve swapped your rear-end gears.
- Tire Size: Adjust the computer for larger-than-stock tires to fix speedometer and shift-point errors.
- Idle Speed: Adjust the RPM at which the car idles.
- TPMS: Adjust or disable tire pressure monitoring alerts (on supported models).
Note: Adjustable Options vary by vehicle
Important Limitation
While these preloaded tunes are great for stock vehicles, they cannot account for major hardware changes. For those modifications, you would need to purchase a Custom Tune from a professional tuning shop and load it onto the X4 (which has up to 10 slots for custom files).