I t took us million of years to evolve into human beings. The case with IC engines too is not very different, and the frugal yet powerful engines that power our cars today are a result of over several decades of work. The development curves of engines from different manufacturers may have been different, but they tried to modify certain key parameters to bring engines at this stage. VTVT / VVT etc. can be put under one such technology group. In this article, we discuss it in detail. 1. DDIS (Diesel direct injection system) refers to the type of diesel engines for cars . They are equipped with turbochargers, which increase availability of oxygen, resulting in better combustion thus increasing the engine performance. 2. Variable valve timing ( VVT ) is the process of altering the timing of a valve lift event, and is often used to improve performance, fuel economy or emissions. It is increasingly being used in combination with variable valve lift systems. It varies the timing