As either two or four cylinders are connected with the drive system, the thrifty power unit is called I2+2 engine
Two two-cylinder engines with a firing interval of 360 degrees, one of which can be completely disconnected from the powertrain whenever applicable. This reduces engine friction torque by 22 percent in the engine speed range relevant to consumption.
Design concept for the I2+2 engine
IAV’s concept drastically reduces friction and improves consumption over conventional approaches, such as cylinder deactivation (CDA) and continuously variable valve lift (CVVL).
The deactivated cylinders can be left idle.The new concept drastically reduces the engine’s friction torque: In the two-cylinder mode, it is 22 percent lower than for the base engine. Naturally, this has consequences for fuel consumption – reducing it by 13.7 percent in the NEDC, which equates to 19 grams of CO2 per kilometer. In cycle 2, which involvesfar higher loads, it falls by 6.2 percent, cutting CO2 emissions by 9 grams per kilometer.
7 second balancer shaft 8 first gear stage 9 second gear stage (Source: Iav Gmbh Ingenieurgesellschaft Auto Und Verkehr)
With conventional wastegated turbochargers or fixed geometry turbochargers (FGT), a turbine flow area cannot be adjusted during operation.
Knocking is abnormal combustion in which the air-fuel mixture ignites prematurely due to exposure to high temperature and pressure, creating an unwanted high-frequency noise. When the compression ratio is increased, the temperature at compression top dead center (TDC) also rises, increasing the probability of knocking.