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Technologies that provide potential for significant improvements in engine efficiency include, engine downsizing/downspeeding (enabled by advanced boosting systems such as an electrically driven compressor), waste heat recovery through turbocompounding or organic Rankine cycle and 48 V mild hybridization. FEV’s Integrated Turbocompounding/Waste Heat Recovery (WHR), Electrification and Supercharging (FEV-ITES) is a novel approach for integration of these technologies in a single unit. This approach provides a reduced cost, reduced space claim and an increase in engine efficiency, when compared to the independent integration of each of these technologies. This approach is enabled through the application of a planetary gear system. Specifically, a secondary compressor is connected to the ring gear, a turbocompounding turbine or organic Rankine cycle (ORC) expander is connected to the sun gear, and an electric motor/generator is connected to the carrier gear.

Substitution of diesel fuel with natural gas in heavy-duty diesel engines offers significant advantages in terms of operating cost, as well as NOx, PM emissions and greenhouse gas emissions. However, the challenges of high THC and CO emissions, combustion stability, exhaust temperatures and pressure rise rates limit the substitution levels across the engine operating map and necessitate an optimized combustion strategy. Reactivity controlled compression ignition (RCCI) combustion has shown promise in regard to improving combustion efficiency at low and medium loads and simultaneously reducing NOx emissions at higher loads. RCCI combustion exploits the difference in reactivity between two fuels by introducing a less reactive fuel, such as natural gas, along with air during the intake stroke and igniting the air-CNG mixture by injecting a higher reactivity fuel, such as diesel, later in the compression stroke.

In recent years there has been a successful application of engine downsizing in the passenger car market, using boosting technologies to achieve higher specific power and improve fuel economy. Downsizing has also been applied in heavy-duty diesel engines for the on-highway market to improve fuel economy, motivated in part by CO2 emission limits in place under Phase 1 greenhouse gas (GHG) legislation. In the non-road market, with Tier 4 emission standards already being met and no current plan for a GHG emission requirement, there has been less activity in engine downsizing and the drivers for this approach may be different from their on-highway counterparts. For instance, manufacturers may consider emission regulation break points as a motivation for engine displacement targets. Many non-road applications demand a relatively high low-end torque and support the use of higher displacement engines.