3-stage VTEC

3-stage VTEC

Three-stage VTEC is a multi-stage implementation of VTEC and VTEC-E (colloquially known as dual VTEC), implemented in some 1995–present D series engines, allowing the engine to achieve both fuel efficiency and power. VTEC-E (for "Economy") is a form of VTEC that closes off one intake valve at low RPMs to give good economy at low power levels, while "VTEC" is a mode that allows for greater power at high RPMs, while giving relatively efficient performance at "normal" operating speeds. "Three-stage VTEC" gives both types in one engine, at the cost of greater complexity and expense.