AFM & DFM
How GM cylinder deactivation works, what fails, and the ways to deal with it.
AFM Disabler vs DOD Delete vs Tune: Which Is Right for Your 5.3 or 6.2 GM?
Three ways to keep a GM V8 on all eight cylinders, what each one physically changes, which vehicles a plug-in disabler fits, and the six questions that decide it.
Sep 24, 2026 · 313 views
What Is Active Fuel Management? GM's AFM Explained
What GM cylinder deactivation actually does: the request chain that drops a V8 to four cylinders, which engine families and model years carry the system, how AFM differs from DFM, and where the lifter duty sits.
Sep 20, 2026 · 244 views