Automotive Internal Combustion Engines

Internal combustion engines for motor vehicles, with spark ignition and compression ignition, constitute a more than mature technology that is nevertheless constantly evolving both due to the need to contain pollutant emissions in transport and because it is driven by a very lively global market which, in terms of innovation, it is second only to that of some consumer electronics devices. Numerous improvements, which have also recently occurred, have already allowed, and will allow in the future, to optimize combustion and the use of fuels, reducing fuel consumption and emissions from vehicles. The innovation concerns both light vehicles, on which this brief is focused, and heavy vehicles.

Examples of advanced technologies for spark ignition engines include direct fuel injection, electronic management of valve timing for intake and exhaust valves, variable compression ratio, prechamber combustion and water injection. For diesel engines, on the other hand, we can mention, for example, the injection by compression with homogeneous charge and the optimization of the cooling system. Technologies and interventions common to both engines are instead the reduction of friction losses, cylinder deactivation, downsizing and supercharging, to achieve the electrification of the powertrain in hybrid systems. Finally, it is worth mentioning the Atkinson cycle, already on the market for many years in hybrid vehicles, which offers advantages in terms of cycle efficiency (energy efficiency).