Which GM engines have cylinder deactivation?
Several General Motors (GM) engines feature cylinder deactivation technology, which allows the engine to temporarily shut off some of its cylinders to improve fuel efficiency. This technology is particularly useful in larger engines that power trucks, SUVs, and high-performance vehicles.
What is Cylinder Deactivation?
Cylinder deactivation is a fuel-saving technology that allows an engine to temporarily shut off some of its cylinders when they are not needed, such as during light-load driving conditions. This reduces the engine's displacement and lowers the amount of fuel consumed, leading to improved fuel economy. When more power is required, the deactivated cylinders are reactivated seamlessly to provide the necessary performance.
GM Engines with Cylinder Deactivation
GM has implemented cylinder deactivation technology in several of its engine families, including:
- Gen V Small Block V8 Engines: These include the 5.3L, 6.2L, and 6.6L V8 engines used in various Chevrolet, GMC, and Cadillac models. These engines can deactivate up to four cylinders to improve fuel efficiency.
- Gen V Small Block V8 Engines with Dynamic Fuel Management: Newer versions of the 5.3L and 6.2L V8 engines feature an advanced cylinder deactivation system called Dynamic Fuel Management, which can deactivate any combination of cylinders to optimize efficiency.
- 3.6L V6 Engines: Some GM vehicles, such as the Chevrolet Traverse and Buick Enclave, are equipped with a 3.6L V6 engine that can deactivate two cylinders to save fuel.
These cylinder deactivation systems are designed to seamlessly transition between different cylinder configurations, providing a balance between performance and fuel efficiency based on driving conditions.
Benefits of Cylinder Deactivation
The primary benefit of cylinder deactivation is improved fuel economy, as the engine can operate more efficiently by reducing the number of active cylinders when full power is not required. This technology can lead to fuel savings of up to 7% in real-world driving conditions. Additionally, cylinder deactivation can help reduce emissions and engine wear, as the deactivated cylinders do not contribute to the engine's overall workload.
Overall, cylinder deactivation is an important technology that allows GM to offer powerful, fuel-efficient engines in its vehicles, particularly in larger models that require more displacement for performance.
Which GM engines do not have an AFM?
The LM2 Duramax 3.0L turbo-diesel, the L8T 6.6L V8, and the LS3 have neither AFM nor the latest version, called DFM (Dynamic Fuel Management). In addition, some 5.3L V8s from 2021 and 2022 don't include either fuel-saving system due to semi-conductor shortages manufacturers were dealing with during that time.
What year to avoid AFM?
The AFM system is supposed to disable engine cylinders when you're not using them to help you save gas. Unfortunately, it was faulty, especially in the years between 2010 and 2014, which are definitely some of the Chevy Silverado model years to avoid.
What year did GM have cylinder deactivation?
General Motors was the first to modify existing production engines to enable cylinder deactivation, with the introduction of the Cadillac L62 "V8-6-4" in 1981.
Why is 2014 the worst year for Silverado?
Of the best and worst years for the Chevy Silverado 1500, the 2014 model year is the worst of the worst. With over 250 problems reported and 19 recalls, this model is reputable for electrical issues, airbags not deploying or failing to inflate, and transmission oil cooler lines prone to failure.
Can you turn off cylinder deactivation?
Unfortunately, optimizing the system requires that we adjust the triggers that make us step from all cylinders to shut-off mode and back again. Looking at popular aftermarket tuning software options, there are several ways to disable the system, based on rpm, VSS, gear, voltage, run time, and more.
Does GM 6.2 have cylinder deactivation?
DFM in GM engines can shut down any number of cylinders, following 17 different patterns, depending on driving conditions and throttle input. The system helps GM's OHV 6.2L V-8 achieve a 2-mpg (0.9 km/L) gain in real-world fuel efficiency without sacrificing any of the engine's 420 hp and 460 lb. -ft.
What year did the 6.2 get AFM?
The 5.3L engine had it from 2007+, the 2009+ hybrid Escalade, and 2010+ 6.2L engines were equipped with it. It's very possible you could still have a collapsed lifter, but the 2009 6.2L doesn't have AFM. Lifter failure is still seen but just not as often.
Do all 5.3 have cylinder deactivation?
Yes. 5.3 and 6.2, unless your 19-22 5.3 is stated with the window sticker (idk if theres a code) that the 5.3 is to come without DFM. 2500's never have or will come with AFM/DFM.
Can GM AFM be turned off?
The engine will have 25 less pounds of compression in those four cylinders which can result in a misfire code. You will need to turn off the AFM system using a computer programmer or custom tuning. It's a little more work, but it's recommended that you plug the pressure relief valve in the oil pan.
How do I know if my 5.3 has Active Fuel Management?
Engine Cover Markings — Many GM engines equipped with AFM will have a label or badge on the engine cover indicating “AFM” or “Active Fuel Management.”
