The Banks Derringer Tuner is different from a basic inline box because it communicates with the truck through OBD-II and uses live vehicle data to control how added power is delivered. That matters on a 6.7L Ford because power isn’t just about fuel rail pressure. Exhaust temperature, ambient pressure, regen status, accelerator position, coolant temperature, and transmission slip all affect how much power the truck can safely use. Instead of blindly adding fuel, Derringer uses dynamic tuning to adapt in real time. It rolls power in progressively, adjusts for altitude and temperature, limits added power when EGT climbs, backs off during overheating or excessive slip, and transitions to a safer sustained towing level under long wide-open-throttle use. That keeps the engine and transmission out of the tug-of-war that simple fuel-only tuners create. It also delivers a real fail-safe advantage. With ActiveSafety, if the unit detects a problem or loses power, it returns the truck to stock power instead of dropping the vehicle into a reduced-power event. That’s the difference between a smart tuner and a box that only knows how to add fuel.
Gale Banks opens by arguing that the Derringer is the only inline tuner worth considering for the 2017-2019 Ford 6.7L Super Duty because it is the only "smart" tuner in the group. His central claim is that OBD connectivity allows the Derringer to protect the truck while still delivering the advertised power increase. To support that claim, Banks says the company purchased and tested competing tuners on the same truck, on the same day, in the same weather, on the same dyno, and over the same road course with the same driver.
The comparison group included aFe, AG Diesel, TS Performance, and Stealth. Banks also states that Stealth, Doctor Performance, and Diesel Dominator are effectively the same product sold under different labels, describing them as the same box with different stickers. The point of the comparison is not just peak output, but how each tuner makes power and whether it can do so safely under changing operating conditions.
The factory rating for the 6.7L Super Duty is given as 440 horsepower and 925 lb-ft at the flywheel, but Banks emphasizes that what matters to the owner is the power that actually reaches the road. In stock form, the test truck produced 389 horsepower at the road surface, with peak power occurring a little after 2,800 rpm.
With the Derringer installed, the truck reached 443 horsepower at the road surface. That represents a 54-horsepower peak-to-peak gain over stock, with a best gain of 59 horsepower at the strongest point in the curve. The aFe Scorcher, which modifies both fuel and air, produced a 28-horsepower peak-to-peak gain and a best gain of 33 horsepower. The TS MP8, described as a fuel-only tuner, reached 414 horsepower for a 25-horsepower peak-to-peak gain and a best gain of 26 horsepower. The Stealth unit and its related rebrands reached 412 horsepower, good for a 23-horsepower gain and a 24-horsepower best gain. AG Diesel trailed the group at 401 horsepower, with only a 12-horsepower peak-to-peak gain and a 14-horsepower best gain.
Banks then shifts to torque, which is especially important for diesel truck owners. In stock form, the truck produced 829 lb-ft at the road surface. With the Derringer, output increased to 892 lb-ft, a 63 lb-ft peak-to-peak gain. More importantly, Banks highlights a best gain of 106 lb-ft at the strongest point in the curve.
The aFe Scorcher reached 862 lb-ft, which amounted to a 33 lb-ft peak-to-peak gain and a best gain of 64 lb-ft. The TS MP8 produced 867 lb-ft, for a 38 lb-ft peak-to-peak gain and a 50 lb-ft best gain. The Stealth unit reached 863 lb-ft, delivering a 34 lb-ft peak-to-peak gain and a 43 lb-ft best gain. AG Diesel again finished last at 850 lb-ft, with a 21 lb-ft peak-to-peak gain and a 25 lb-ft best gain. Banks presents these results as evidence that the Derringer not only leads in peak numbers, but also provides stronger gains across the usable operating range.
Banks explains the performance gap by focusing on how each tuner works. According to him, Stealth, AG Diesel, and TS Performance intercept the fuel-rail-pressure signal, alter it, and send the modified signal back to the truck's ECU. In his description, these are essentially one-sensor devices that increase fueling without broader awareness of engine operating conditions. The aFe unit goes a step further by altering both the fuel-rail-pressure signal and the manifold absolute pressure, or MAP, signal, so it adds both fuel and air.
The Derringer differs because it is connected through an OBD cable to the truck's ECU. Banks says this makes it the only smart tuner in the comparison. Rather than blindly adding fuel, it dynamically adjusts added power based on live vehicle data. Banks refers to this strategy as adaptive tuning, and says the Derringer makes adjustments 250 times per second. That ECU connection is presented as the key reason it can maintain performance while also protecting the engine, transmission, and aftertreatment system.
A major part of the Derringer's strategy is exhaust gas temperature control. Banks says the 6.7L Ford begins limiting power at 1,450 degrees exhaust gas temperature into the turbine in order to keep maximum EGT below 1,500 degrees. Because the Derringer knows the temperature through OBD data, it begins limiting its own added power at the same 1,450-degree threshold, mirroring the factory ECU's protective behavior.
Altitude compensation is another example of adaptive tuning. At high altitude, ambient air pressure drops, which affects available oxygen and turbocharger operation. Banks says the Derringer senses ambient air pressure and controls the turbocharger to maintain added boost and power as altitude increases. Competing tuners, by contrast, continue adding fuel without understanding the reduced air density. That can drive EGT upward, after which the factory ECU pulls power back. Banks describes this as a tug-of-war between the tuner and the ECU: the tuner adds fuel, the ECU removes power to cool the engine, then the cycle repeats. On a long grade, he says, the driver can actually feel those cycles.
The Derringer also monitors diesel particulate filter regeneration. During a regen event, Banks says the Derringer is aware of what the truck is doing, while the competing boxes are not. Accelerator pedal position is also monitored so the Derringer can roll in added power progressively. This is intended to improve part-throttle fuel economy while still delivering maximum power when the driver actually requests it.
Banks places particular emphasis on coolant temperature management, especially for trucks towing heavy loads on long grades in hot weather or at high altitude. Under those conditions, the cooling system has a harder time rejecting heat to the atmosphere while the engine is producing high power. The Derringer uses coolant temperature data to decide when and how much additional power to provide.
No added power is delivered below 120 degrees coolant temperature. Added power is then ramped in, becoming fully available above 150 degrees. If coolant temperature rises too far, the Derringer begins removing added power at 230 degrees, and all additional power is removed above 240 degrees. Banks contrasts this with the competing tuners, which he says have no awareness of coolant temperature at all.
For towing, the Derringer also manages sustained wide-open-throttle operation. Banks says it allows 30 seconds of wide-open throttle before transitioning to the recommended power level for sustained trailer towing. This is presented as a way to provide strong short-term performance without overstressing the truck during long climbs.
Beyond engine protection, Banks says the Derringer also protects the transmission. It modulates added power if it detects excessive slip, including torque-converter-clutch slip. He also references TransCommand, describing it as a strategy that uses key engine and transmission parameters to enhance shift performance and improve transmission longevity. Because competing tuners lack the necessary OBD data, he says they continue adding power regardless of transmission condition, which can contribute to excessive slip.
Banks then introduces what he calls ActiveSafety. The Derringer includes a watchdog circuit that monitors the tuner itself. Under normal operation, signals pass through relays, are processed by the Derringer CPU, and then sent to the truck's ECU. If the Derringer detects a fault or loses power, it enters a fail-safe mode that seamlessly returns the truck to stock power. Banks contrasts this with the competing tuners, which he says can trigger multiple trouble codes and a reduced-engine-power condition if they lose power or fail.
To demonstrate the difference, Banks performs a road test with one of the Stealth-style boxes installed. He describes it as representative of several rebranded products and characterizes it as a one-wire setup that interrupts only the fuel-rail-pressure sensor. During the test, he accelerates the truck in manual mode, brings engine speed up, floors the accelerator, and then cuts the 5-volt power feeding the tuner. According to his account, the accelerator pedal immediately becomes unresponsive and the engine effectively shuts down, leaving the truck with no power.
He then repeats the test with the Derringer installed. Again he accelerates the truck, applies full throttle, and interrupts power to the tuner. This time, the truck continues pulling under stock power rather than dropping into a failure condition. Restoring power brings the added performance back, and removing power again returns the truck to stock operation without drama. Banks presents this as proof that the watchdog and fail-safe circuitry work as intended.
The recap concludes with Banks framing the Derringer as the only tuner in the group that combines measurable power gains with adaptive control, engine and transmission safeguards, and a true fail-safe strategy. His overall argument is that inline tuners that simply manipulate one or two sensor signals may add some power, but without OBD awareness they cannot properly manage EGT, altitude, regen, pedal input, coolant temperature, towing conditions, or transmission slip.