When you’re towing, the truck doesn’t live at peak horsepower. It works in the mid-range, and that’s exactly where we focused the Derringer High Output for the 2024-25 Duramax L5P. By controlling mid-range boost, we added a big torque increase between 2200 and 2800 rpm, where merging, climbing, and passing actually happen. That matters more than a headline dyno number. With a 20,065-lb gross weight, the stock truck needed 1,279 feet to reach 70 mph. With Derringer on level 6, it got there in 1,085 feet. On a 7% grade from 45 to 70 mph at 20,000 lb, Derringer cut passing time from 23.6 seconds to 15.1 seconds and reduced passing distance by 756 feet. Less time waiting on the truck means less time stuck in the merge lane or on the wrong side of the road. Derringer delivers up to +178 lb-ft and +86 hp, but the real win is where that power shows up. Six power levels let you tune for economy, work, or max output, and Banks iDash Pro gives you the real-time powertrain data and in-cab control to manage it while you drive. Add the available Banks Ram-Air Intake System, Monster-Ram, and Banks Boost Tube Upgrade Kit, and drivability only gets better.
The video introduces the Banks Derringer High Output for the 2024-2025 Duramax L5P and frames it around real towing situations rather than unloaded peak-power claims. Banks states that the system adds 178 lb-ft of torque and 86 horsepower, but emphasizes that the important change is not just the size of the gain. The focus is where that torque and horsepower are delivered and how the truck was tested under load.
Banks explains that the calibration was developed to increase torque across the engine's working range, specifically from 2,200 to 2,800 rpm. According to the presentation, this was achieved by controlling mid-range boost. The point is straightforward: mid-range boost produces mid-range torque, and mid-range torque is what matters when a truck is towing, merging, climbing, or passing.
Rather than concentrating on top-end output, the tuning strategy targets the part of the rpm band where a working truck spends its time. Banks ties this approach to prior military engine work, stating that it built 26,000 JLTV engines for the Army using the same general tuning philosophy now applied to the Duramax. The message is that the calibration is based on usable loaded performance, not just headline dyno numbers.
The recap then shifts to the driving situations that place the greatest demand on a tow vehicle. Banks argues that the mid-range is where drivers actually work their trucks: accelerating up an on-ramp with a trailer, trying to merge into traffic already moving at highway speed, or pulling hard on a grade.
The example given is a typical interstate on-ramp. Banks says many on-ramps are about 1,500 feet long, while the speed of the merging traffic is often dictated by semis traveling around 70 mph. That leaves only about 1,000 feet to accelerate to 70 mph before entering traffic. As trailer weight increases, that task becomes more difficult, which is why Banks chose to evaluate the Derringer in a loaded, real-world merging scenario rather than in an unloaded sprint.
To simulate that merge, Banks loaded a Tacoma into a trailer and hitched it to a 2024 Duramax. The combined gross vehicle weight was 20,065 pounds. Testing was performed on a straight, flat section of road, and the truck was placed in four-wheel drive to prevent wheelspin from affecting the results. Banks then ran a series of acceleration tests to measure how much road was required to reach 70 mph.
In stock form, the 2024 Duramax needed 1,279 feet to reach 70 mph. With the Derringer tuner set to Level 6, the maximum-power setting, the same rig reached 70 mph in 1,085 feet. That is a reduction of 194 feet. Banks presents this as a practical safety margin: the Derringer-equipped truck reaches merging speed within the available distance, while the stock truck is still accelerating beyond the intended merge zone and remains mixed in with slower heavy traffic.
The second test addresses an even more demanding situation: passing while towing uphill. Using a gross weight of 20,000 pounds, Banks measured the time and distance required to accelerate from 45 to 70 mph on a 7 percent grade at wide-open throttle. This test is intended to represent the kind of two-lane passing maneuver that leaves a truck exposed in the oncoming lane while pulling hard under load.
In stock form, the 2024 Duramax required 23.6 seconds and 2,092 feet to accelerate from 45 to 70 mph. With the Derringer installed, the truck completed the same run in 15.1 seconds and 1,336 feet. That cuts 8.5 seconds and 756 feet from the passing maneuver. Banks summarizes the result as 36 percent less time spent on the wrong side of the road, again reinforcing that the product's value is tied to loaded mid-range performance rather than peak output alone.
Banks says the Derringer includes six power levels, with each level using its own custom calibration rather than a single tune with simple scaling. Level 2 is described as a fuel-economy tune. Levels 3 and 4 are intended for work use, while Levels 5 and 6 are aimed at maximum performance.
This tiered structure suggests that the system is meant to be adaptable to different operating conditions, from efficiency-focused driving to towing and full-power use. The video does not go into the detailed calibration differences between levels, but it makes clear that the tuning is organized around practical use cases rather than a one-setting approach.
The Derringer is paired with the new iDash Pro, which Banks describes as a powertrain information and control center. Through iDash, the driver can monitor real-time engine and powertrain data that GM does not show on the factory dashboard. The system also serves as the interface for adjusting the Derringer's power level while driving.
Banks adds that iDash can also control throttle response when used with a Banks PedalMonster. In that configuration, the display becomes more than a gauge package; it acts as the central control point for both tuning level selection and accelerator-response adjustment.
Banks describes the Derringer system as plug-and-play and intended for garage installation, indicating that it is designed to be installed without extensive fabrication or major vehicle modification. The video closes by noting that power and drivability can be improved further with additional Banks airflow components.
Those supporting parts include the new 50-state-compliant Ram-Air intake, Monster-Ram, and boost tubes, all of which are said to be available now. The recap does not provide separate test numbers for those components in this segment, but Banks presents them as complementary hardware that can further support the Duramax's airflow and overall performance.
