How GMC's Active Fuel Management & Dynamic Fuel Management Save You Money

As a family-owned and operated dealership with a 50-plus-year history of exceeding customer expectations, customers know that Elk Grove Buick GMC is the best location for Buick and GMC vehicles. From the iconic Buick Envista and always exciting Buick Encore GX, Buick Envision, and family-friendly Buick Enclave, to the ultra-powerful GMC Sierra 1500 and next-level GMC Sierra 2500 and 3500, customers know that Elk Grove Buick GMC has the best deals in Elk Grove, California.

GMC and Buick have long been associated with multiple firsts. These engineering-driven innovations are ultimately why both brands are so cherished by customers, and why General Motors continually produces high-end, high-performance vehicles year after year. Two technologies that attest to that engineering-first mindset are GM’s Active Fuel Management (AFM) and Dynamic Fuel Management (DFM) systems.

How Do Both Save You Money?

Both AFM and DFM reduce fuel consumption by temporarily shutting down cylinders when full power isn't needed. Less fuel burned equals direct savings at the gas station. For Elk Grove commuters driving on Highway 99 or Interstate 5, these systems lower overall operating costs without you changing how you drive.

What Is Active Fuel Management (AFM)?

Active Fuel Management (AFM) has a long and well-established history. Originally called Displacement on Demand (DOD), this solution was first launched on the 2005 Chevrolet TrailBlazer – specifically the 5.3-liter V8 model. This ingenious system allowed the TrailBlazer to switch from 8 to 4 cylinders as needed to improve fuel efficiency.

Over the next two decades, AFM became smoother and far more efficient. New upgraded lifters, improved engine mounts, revamped exhaust tuning, and an improved Engine Control Unit (ECU) meant both fuel injection and ignition timing became more efficient.

Now, General Motors (GMC & Buick) vehicles with AFM benefit from a system that easily turns off half an engine’s cylinders while driving, ensuring you use less gas on long drives and highway cruising. You don’t have to change your driving habits to benefit from this increased fuel efficiency. Achieving better mileage is entirely managed by the AFM system. Given the always-increasing costs of fuel, having a GMC or Buick with AFM ensures the highest level of fuel efficiency.

The benefit of AFM is that there is no loss of power when heavy hauling or when needing to accelerate. Instead, you can cruise as needed on highways, and the AFM system optimizes fuel efficiency as you drive. AFM is only available on V6s and V8s. The Chevrolet Silverado 1500 (5.3-Liter V8) and GMC Sierra 1500 (5.3-Liter V8) are the two 2025 models using AFM.

What Makes Dynamic Fuel Management (DFM) Smarter?

Dynamic Fuel Management (DFM) takes it to the next level. DFM is an upgrade over AFM in that the DFM system provides more accurate control over the cylinders, immediate, real-time adjustments, and improved fuel efficiency. More importantly, DFM isn’t just relegated to long-distance, highway driving. The system works in city driving.

With DFM, you’re able to optimize fuel consumption for everyday stop-and-go traffic. Whether you’re on the highway, backcountry roads, or driving in the city, DFM ensures your fuel consumption is continuously maximized.

As impressive as AFM is, it’s important to note that DFM has largely replaced AFM for GMC 2026 models with V8 (8 Cylinder) engines. This means vehicles like the 2026 GMC Sierra 1500, 2500, and 3500, as well as the GMC Yukon, are running the DFM system.

Why DFM Is Largely Replacing AFM

Ultimately, DFM is a system that maximizes the number of combinations within a V8 engine. This means that DFM is able to maximize these variations to a much greater extent than AFM. While AFM can only switch from 8 cylinders to 4, DFM is able to maximize combinations well beyond just half the cylinders. In addition, AFM is only activated under specific driving conditions like highway cruising, whereas DFM is continuous and applies to city, highway, and stop-and-go driving.

Save Money On Every Drive: Elk Grove to Folsom and Beyond

Whether you commute from Elk Grove to Sacramento, head to Stockton or travel to Vacaville, AFM and DFM deliver real savings. Less fuel burned means more money in your pocket. DFM's city driving optimization is especially helpful for Bay Area traffic and local stoplights along Laguna Boulevard.

Test Driving Your Next Buick or GMC at Elk Grove Buick GMC

The Elk Grove Buick GMC team is committed to making every experience with our dealership a relaxing and enjoyable one. Our focus is on ensuring you have a stress-free and worry-free experience where everyone you deal with provides first-rate customer service. From a sales team that stops at nothing to ensure you get the Buick or GMC of your dreams, a finance team with an unbeatable record for incredible financing, and our always-ready parts and service team, you’ll love dealing with Elk Grove Buick GMC.

To learn more about the many Buick and GMC vehicles or to take one for a test drive, call our sales team at 916-691-2700 or contact us online.

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Frequently Asked Questions About AFM and DFM

Which GMC models have Active Fuel Management?

For the 2025 model year, certain V8 models like the GMC Sierra 1500 with the 5.3L V8 use AFM. Always check window sticker or consult our Elk Grove team.

Is DFM better than AFM for city driving?

Yes. DFM continually adjusts cylinder activation (from 1 to 8 cylinders) in real time, giving better fuel economy in stop-and-go conditions. AFM mainly activates during highway cruising.

Does cylinder deactivation affect performance when towing?

No. Both AFM and DFM automatically deactivate when you need full power, such as towing a trailer, climbing grades, or heavy acceleration. You get the fuel savings when demand is low.

What 2026 GMC vehicles use DFM?

The 2026 GMC Sierra 1500, Sierra 2500HD, Sierra 3500HD, and GMC Yukon (V8 configurations) feature DFM as the advanced fuel management system.

How much money can I save with DFM?

Savings vary based on driving mix, but GM estimates DFM improves real-world fuel economy by reducing cylinder usage up to 15% on average compared to a fixed V8 operation. Over a year, that can mean hundreds of dollars saved at California fuel prices.

See detailed specs and compare fuel-saving technologies on our Model Research page or browse All Inventory.