The primary difference between V6 and V8 engines is that a V6 has six cylinders, while a V8 has eight cylinders. Both V6 and V8 engines have cylinders arranged in a V-configuration. In this configuration, the engine contains two rows of three or four cylinders that are parallel to each other and extend out from the engine block in a V-shape.
V6 and V8 engines are the most popular configurations for consumer vehicles. These engines are most commonly used in trucks, SUVs, sports cars and luxury cars because they generally provide more power than the I4 engine.
In addition to configuration, it is important to consider engine volume or displacement, typically measured in liters or cubic centimeters, when comparing engine size. Displacement measures the volume of air that the pistons inside all the cylinders displace, which gives consumers a better idea of the engine's size and combustion capabilities.
Not all six- or eight-cylinder engines are in the V configuration. Inline, flat and radial engines are also possible, though only inline six- and eight-cylinder engines are typically found in cars and trucks. In an inline engine, all the cylinders are lined up in one straight row, which produces a powerful engine but usually requires a very large engine bay.