A "cubic 6.2L engine" refers to a gasoline or diesel internal combustion engine with a total displacement of 6.2 liters. The "cubic" part is an older, less precise way of referring to the engine's displacement. While technically displacement is measured in liters (or cubic centimeters), the term "cubic" is sometimes used colloquially to emphasize the three-dimensional nature of the engine's cylinders.
In short, it's just a slightly more descriptive way of saying it's a 6.2-liter engine. The size indicates a relatively large engine, commonly found in larger vehicles like trucks, SUVs, or performance cars.
