Active fuel management, or AFM, is a system that helps improve fuel efficiency in modern engines. The AFM system uses computers and sensors to monitor engine performance and selectively deactivates cylinders when full power is unnecessary. This allows the engine to operate on fewer cylinders, reducing fuel consumption.

An AFM delete kit removes the AFM components, so the engine runs in a full-time V8 mode. This provides more power and a performance-oriented driving experience at the cost of slightly lower fuel economy. Drivers who install an AFM delete kit get the best of both worlds - enhanced power and responsiveness and AFM's fuel efficiency under normal driving conditions.

The AFM delete kit allows the vehicle's powertrain computer to disable the AFM system so that all cylinders remain on fire constantly. This results in a more powerful and responsive ride, especially during acceleration. At the same time, the engine still benefits from efficiencies when cruising at constant speeds on the highway or city streets. So, drivers enjoy more power and performance when they want it while still achieving relatively good fuel mileage the rest of the time.

In summary, an AFM delete kit provides enthusiasts and performance vehicle owners with an easy way to unlock more power and acceleration from their engines without making other mechanical modifications. By deleting the AFM system, all available cylinders remain permanently engaged for a dynamic driving experience that is more responsive and thrilling. At the same time, the engine can still operate efficiently under normal driving conditions for acceptable fuel economy.

Understanding the AFM System

AFM stands for active fuel management. It is a technology developed by General Motors to improve fuel efficiency and reduce emissions. The AFM system works by deactivating 4 out of the eight cylinders under light load driving conditions when maximum power is not needed. This is done through a process called cylinder deactivation.

When full power is not required, such as at cruising speeds on the highway, the AFM system seamlessly deactivates the unused cylinders. This allows the engine to operate on fewer cylinders, which lowers the amount of fuel injected and burned. Once more power is needed, such as when accelerating, the system reactivates the cylinders quickly and smoothly. This provides a driving experience that is balanced and responsive without impacting acceleration or high-speed performance.

AFM provides benefits like improved fuel economy, reduced emissions, and a smaller environmental footprint. However, many performance vehicle owners feel it reduces engine power, responsiveness, and character. Therefore, an AFM delete kit is popular to bypass the system and keep all cylinders permanently active for a more aggressive driving feel. By deleting AFM, up to 20% more power can reportedly be achieved, along with faster acceleration and a more thrilling overall driving experience.

In summary, AFM is an advanced fuel-saving technology that provides environmental benefits. But it is not ideal for drivers who prefer powerful, high-performance vehicles. The engine can operate at full capacity for maximum power, torque, acceleration, and an exhilarating ride by deleting the AFM system with an AFM delete kit. The trade-off is slightly lower fuel efficiency when AFM is not engaged. For many, the power and performance benefits outweigh these efficiency losses.

Active Fuel Management Delete Kit

What Is an AFM Delete Kit?

An AFM delete kit is an aftermarket product designed to bypass GM vehicles' active fuel management system. It allows the engine's computer to disable AFM, keeping all cylinders permanently active instead of deactivating some during light-load driving. This results in enhanced power, acceleration, and performance.

An AFM delete kit typically includes the following components:

  • An engine tuner or programmer: This is used to reprogram the vehicle's engine computer and disable the AFM system. Some tuners allow more aggressive camshaft profiles and fuel curves to maximize power gains.
  • New spark plugs: The stock spark plugs may not produce an optimal spark when more power is in demand. High-performance spark plugs generate a bigger, hotter spark for complete combustion.
  • Air filter upgrade: A high-flow air filter allows more airflow into the engine, producing more power. Some kits include performance air filters and intake tubing.
  • Installation hardware: Basic tools and screws/bolts are included to properly install the engine tuner, air filter, spark plugs, and other components.
  • Instructions: Step-by-step instructions walk owners through uninstalling the old AFM components, installing the delete kit parts, and programming the engine tuner to disable AFM.

After installing an AFM delete kit, the engine operates at full capacity whenever the accelerator is pressed. This significantly increases horsepower, torque, acceleration, and a more aggressive overall driving feel than when AFM was engaged. The exact power gains depend on the delete kit's specific vehicle, engine, and components. But 20-40 horsepower increases are common, especially at high RPM.

In summary, an AFM delete kit provides a simple and effective solution for unlocking more power and performance from GM vehicles with AFM technology. By bypassing the system, the engine can run freely with all cylinders active for faster acceleration, stronger towing/hauling ability, and an exciting riding experience.

Benefits of Using an AFM Delete Kit

  • More power and acceleration. With AFM disabled, the engine can operate at maximum capacity. This allows faster acceleration, 0-60 mph times, and higher top speeds. Power gains of 20-40 horsepower are typical after installing an AFM delete kit.
  • Improved towing and hauling capability. The additional power and torque with AFM deleted means the vehicle can tow heavier loads with better acceleration and flexibility. It's ideal for towing boats, horse trailers, campers, and more.
  • Exhilarating performance. Driving with all cylinders firing at once provides an energetic, forceful feel. Every press of the accelerator triggers a refreshing burst of acceleration. It makes for an exciting, adrenaline-fueled driving experience.
  • Customization opportunity. An AFM delete kit allows further engine customization through tuners, cams, headers, exhaust systems, and other performance parts. The engine computer has already been reprogrammed, so other modifications can be made to maximize power and sound.
  • Permanent solution. Unlike other performance upgrades, installing an AFM delete kit provides changes that last. The AFM system deletion is permanent, so the vehicle will always start up and drive with all cylinders active for a powerful feel. There are no consumables to replace or settings to adjust for different driving conditions.
  • Resale value. Some research suggests that deleted AFM vehicles may hold their value better over time. As the performance segment grows, AFM-deleted trucks and SUVs become more sought after. The permanent power and customization options appeal to many buyers beyond traditional muscle car enthusiasts.
  • Cost effective. AFM delete kits provide a relatively affordable way to unlock substantial power and performance gains. They don't require expensive engine replacements or modifications like supercharging, turbocharging, or cylinder heads. The costs tend to be a fraction of other high-performance upgrade options.

In summary, deleting the AFM system with an AFM delete kit offers several compelling benefits for many drivers and vehicle owners. More power, quicker acceleration, improved towing ability, a thrilling driving experience, and customization opportunities are all possible at an attractive price point. For those wanting the best performance and efficiency, an AFM delete kit strikes a great balance.

AFM Delete Kit Close-up

Drawbacks of Removing the AFM System

While AFM delete kits provide significant performance benefits, there are some drawbacks to keep in mind:

  • Lower fuel economy. The main purpose of AFM is to improve engine efficiency and reduce fuel consumption. By disabling the system, fuel economy suffers, especially during light-load driving conditions. Some estimates indicate fuel economy can drop by 10-25% after deleting AFM. Higher-performance driving also increases fuel costs.
  • Increased emissions. With more cylinders actively firing, especially at lower loads, emissions of hydrocarbons and oxides of nitrogen are likely to rise. This is bad for the environment and can make it difficult to pass emissions tests in some areas. Vehicle emissions control systems must work harder to control pollutants when AFM is deleted.
  • Ride quality impacts. The engine may experience more vibration and roughness with all cylinders firing simultaneously, especially at lower RPM. This can translate to a choppier, bumpier ride quality, especially at cruising speeds. Larger diameter performance camshafts can further amplify any ride quality issues.
  • Costlier to maintain. High-performance engines typically require more expensive parts and more frequent replacements. Things like spark plugs, coils, sensors, oxygen sensors, and ignition components need more rapid replacement when subjected to the stresses of all-cylinder operation. Other engine components may also wear out more quickly.
  • Reset challenges. If the check engine light comes on due to a trouble code after deleting AFM, it can be difficult to reset the code. Diagnostic scan tools are needed to properly diagnose and clear codes from a modified engine computer. Some issues may even require a return to the stock AFM programming to reset the light.
  • Turbocharger concerns. Deleting AFM can reduce turbo spooling on turbocharged engines, making the turbocharger less responsive. This is because the turbo spins up based on exhaust velocity from the engine, which decreases with fewer active cylinders. Therefore, the turbo experience may not improve or worsen after deleting AFM.
  • No plug-and-play options. Installing an AFM delete kit requires knowledge of automotive electronics, programming, and mechanical components. Unlike some other bolt-on modifications, it is not a completely plug-and-play process. This can be daunting for the novice or unmechanically inclined vehicle owners.

In summary, while AFM delete kits offer significant performance benefits, it is important to go into the modification with realistic expectations about the potential downsides like lower fuel economy, increased emissions, impacts to ride quality, higher maintenance costs, trouble code issues, turbocharger effects, and the increased mechanical skill required. The pros still outweigh the cons for many, but eyes should be open to all aspects of deleting an AFM system.


In conclusion, an AFM delete kit provides a way for performance enthusiasts to unlock the full potential of their engines by bypassing the AFM system, resulting in enhanced power, acceleration, and a more thrilling driving experience. However, it is important to carefully weigh the benefits against potential drawbacks, such as decreased fuel efficiency, increased emissions, and maintenance costs. Ultimately, deciding to install an AFM delete kit depends on the individual's priorities and preferences, with a focus on balancing performance gains against potential trade-offs.

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