Development of a New 4.0L V6 Gasoline Engine

This paper describes a new 4.0-liter DOHC V6 engine (VQ40DE), which was developed for use on a new compact sport utility vehicle and a compact pickup truck. To meet drivers' demands for acceleration performance when merging into freeway traffic, passing or re-acceleration performance at low speeds in urban areas and hill-climbing or passing performance while towing, the VQ40DE engine produces high output power at its top speed and also generates ample torque at low and middle engine speeds. (More than 90% of its maximum torque is available at engine speeds as low as 2000 rpm.) As the latest addition to the VQ engine series, the VQ40DE engine has the largest displacement in this series. The VQ engine has been named to Ward's Ten Best Engines list for ten straight years, through the continued evolution of its intrinsic technologies to meet market needs. The VQ40DE engine achieves its high performance in part by being a derivative of the VQ35DE engine that was developed for use on a sporty sedan. Development efforts were focused on how to attain an optimum balance among the requirements for performance, quietness and smoothness. This paper provides the details of this VQ40DE engine as well as highlights of individual technologies that contribute to its optimally balanced performance.