The VK engine (formerly known as the ZH) is a V8 piston engine from Nissan. It is an aluminum DOHC 4-valve design. The VK engine was originally based on Nissan's VQ V6 rather than the VH V8 used in previous Q45/Cima models. Changes include: a variable intake manifold, newly designed heads, and a larger drive by wire throttle chamber. The intake manifold directs air through different paths at different engine speeds to optimise low-end torque or high-end horsepower.