In general meaning, downsizing technology should be
understood as a process of reduction of any size in
machinery to get expected result, e.g. mass reduction or
better performance, etc. When referring to the combustion
engine downsizing stands for reducing swept volume with
mainly the same or higher torque and power of the engine
for reduction of CO2 emission and fuel consumption as
well as to save manufacturing costs per power unit. I recognise
three typical downsizing forms: changing cylinder
diameter only, changing piston stroke only and changing
both of them