yes they do.
This is what happens.
when you accelerate the vehicle all 8 cylinders are firing. when you are in no load condition while moving e.g. just keeping the accelerator slightly touched to keep the car rolling at a steady speed on a flat road 4 cylinders are shut down (fuel + spark cut off), As soon as you push the accelerator pedal the 4 dead cylinders come to life.
Its nothing more than a "chay bananay ki machine"
In the old GM Northstar V8s - the engine could vary between 2, 4, 6 and 8 cylinder management, the usual was between 4, 6 and 8 - the 2 cylinder mode was activated when the engine would have overheated to the point of disaster - this 2 cylinder mode would air cool the engine till it could be pulled off the road.