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The engine indicated torque is not delivered entirely to the wheels, because it is lowered by losses, such as the pumping, mechanical friction and front auxiliary power consumption. The front auxiliary belt drive system is a big power consumer-fueling and operating the various accessory devices, such as air conditioning compressor, electric alternator, and power steering pump. The standard fuel economy test does not consider the auxiliary driving torque when it is activated during the actual driving condition and it is considered a five-cycle correction factor only. Therefore, research on improving the front end auxiliary drive (FEAD) system is still relevant in the immediate future, particularly regarding the air conditioning compressor and the electric alternator. An exertion to minimize the auxiliary loss is much smaller than the sustained effort required to reduce engine friction loss.

Increasing regulatory demand to reduce CO2 emissions has led to an industry focus on electrified vehicles while limiting the development of conventional internal combustion engine (ICE) and hybrid powertrains. Hybrid electric vehicle (HEV) powertrains rely on conventional SI mode IC engines that are optimized for a narrow operating range. Advanced combustion strategies such as Gasoline Compression Ignition (GCI) have been demonstrated by several others including the authors to improve brake thermal efficiency compared to both gasoline SI and Diesel CI modes. Soot and NOx emissions are also reduced significantly by using gasoline instead of diesel in GCI engines due to differences in composition, fuel properties, and reactivity. In this work, an HEV system was proposed utilizing a multi-mode GCI based ICE combined with a HEV components (e-motor, battery, and invertor).

For vehicles with internal combustion engines, tailpipe emissions heavily rely on the aftertreatment system, typically a catalytic converter. Modern three-way catalysts (TWC) can very effectively convert the unburnt hydrocarbons (HC), CO, and NOx into non-harmful gases such as H2O, CO2, and N2 when the catalyst brick reaches a relatively high temperature. However, before that catalyst light-off temperature is reached, the emissions conversion efficiency is low, leading to high tailpipe emissions. Due to this light-off temperature requirement of the catalytic converter, the emissions from the engine cold-start period contributes a significant portion of vehicle overall emissions. One of the major reasons for high emissions during cold start is low combustion chamber wall temperatures, lower than the initial boiling temperature of gasoline fuel. This results in fuel film formation, and significantly incomplete evaporation prior to combustion.