If you have a V6 or V8 Silverado or Sierra with AFM or DFM, you can simply defeat those fuel-saving technology by plugging in a $189 device into the OBD-II port ...

A little-known trick disables DFM, or Dynamic Fuel Management, in the Chevy Silverado 1500 pickup as well as the Tahoe and Suburban full-size SUVs.

GM is building the Chevy Silverado and GMC Sierra without AFM/DFM. Here are the models that will no longer offer the fuel-saving tech, and the models that will.