Originally introduced in Europe in the top selling Avensis range, D-4D is widely recognised as one of the most advanced diesel technologies on the market today. Toyota D-4D engines can now be specified on Yaris, Yaris Verso, Corolla, Corolla Verso, Avensis, Avensis Verso, RAV4, Land Cruiser and Previa models.

Until recently, diesel engines relied on relatively simple technology with a low-pressure mechanical injector delivering fuel to a pre-combustion chamber in the cylinder head, where a single ignition - fired by the intense heat of high compression - takes place.

The system was reasonably fuel efficient but lacked precision and refinement, leading to vibration and noise. Fuel combustion can be incomplete, allowing smoke and other emissions to pass into the exhaust.

D-4D components
Toyota's common rail system makes use of a high pressure pump and intelligent, computer controlled injectors to deliver precisely the right amount of fuel, at precisely the right time, directly into the centre of the combustion chamber. D-4D is above all powerful, robust and quite.