Engine Downsizing and Turbocharging for ICE Vehicles

Detailed overview of innovation with sample startups and prominent university research

What it is

  • Engine Downsizing: This involves reducing the size (displacement) of an engine, typically by decreasing the number of cylinders or reducing the volume of each cylinder. Smaller engines inherently consume less fuel, especially at lower loads.
  • Turbocharging: This technology uses a turbine driven by exhaust gases to force more air into the engine’s cylinders. This increased air intake allows for more fuel to be burned, boosting power output from a smaller engine, effectively offsetting the power loss due to downsizing.

Impact on climate action

Engine downsizing and turbocharging drastically reduce emissions from low-carbon ICE vehicles by enhancing fuel efficiency and power output. This innovation diminishes carbon footprints, mitigating climate change by lowering greenhouse gas emissions. Its adoption accelerates the transition towards sustainable transportation, crucial for combating climate crisis and achieving global emission reduction targets.


  • Thermodynamics: Downsized engines operate with higher thermal efficiency at lower loads, meaning they convert more fuel energy into useful power rather than waste heat.
  • Forced Induction: Turbochargers utilize the energy from exhaust gases to compress intake air, increasing the engine’s volumetric efficiency (the amount of air it can draw in).
  • Variable Valve Timing (VVT): VVT systems adjust the timing of the engine’s valves to optimize airflow and combustion efficiency at different engine speeds and loads.
  • Direct Fuel Injection: Direct fuel injection systems deliver fuel directly into the combustion chamber, improving fuel atomization and combustion efficiency.
  • Engine Management Systems: Sophisticated engine management systems control various engine parameters, such as fuel injection timing and ignition timing, to optimize performance and efficiency.

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Prominent Innovation themes

  • Variable Geometry Turbochargers (VGTs): VGTs can adjust the geometry of their turbines to optimize boost pressure at different engine speeds, improving low-end torque and overall efficiency.
  • Twin-Scroll Turbochargers: These turbochargers utilize separate exhaust gas paths to reduce interference between cylinders, improving response time and boosting efficiency.
  • Electric Turbochargers: Electrically driven turbochargers can provide boost even at low engine speeds, eliminating turbo lag and further enhancing low-end torque and fuel efficiency.
  • Mild Hybrid Systems: Combining engine downsizing and turbocharging with mild hybrid systems, which use a small electric motor to assist the engine during acceleration and recover energy during braking, can further improve fuel economy.

Sample Global Startups and Companies

  • Tula Technology:
    • Technology Focus: Tula Technology specializes in engine control systems and optimization solutions, particularly focusing on cylinder deactivation and variable displacement technologies. These technologies enable engine downsizing without sacrificing performance or efficiency.
    • Uniqueness: Tula’s unique approach lies in its ability to dynamically adjust the operation of individual engine cylinders, optimizing fuel consumption and emissions in real-time based on driving conditions.
    • End-User Segments: Their solutions are relevant across various automotive segments, including passenger cars, light trucks, and commercial vehicles, where fuel efficiency and emissions reduction are significant concerns.
  • MAHLE:
    • Technology Focus: MAHLE is a global automotive supplier that offers a range of engine components and systems. In the context of engine downsizing and turbocharging, MAHLE likely provides advanced turbocharger technology, as well as lightweight engine components and thermal management systems.
    • Uniqueness: MAHLE stands out for its comprehensive approach to engine efficiency, offering a broad portfolio of products and solutions that optimize performance while reducing emissions and fuel consumption.
    • End-User Segments: Their solutions cater to automotive manufacturers across the spectrum, from passenger cars to commercial vehicles, as well as racing and high-performance applications.
  • BorgWarner:
    • Technology Focus: BorgWarner is a global leader in providing advanced propulsion solutions for vehicles. In the context of engine downsizing and turbocharging, BorgWarner offers turbocharger technology, variable turbine geometry systems, and electrically assisted turbochargers.
    • Uniqueness: BorgWarner’s strength lies in its extensive expertise in turbocharging technology and its ability to develop innovative solutions that improve engine performance and efficiency while meeting stringent emissions standards.
    • End-User Segments: Their solutions are utilized across the automotive industry, including passenger cars, light trucks, commercial vehicles, and off-highway applications, where engine downsizing and turbocharging play a crucial role in achieving performance and regulatory targets.

Sample Research At Top-Tier Universities

  • Technical University of Munich (TUM):
    • Technology Enhancements: TUM researchers are concentrating on advancements in engine downsizing and turbocharging technologies to enhance the efficiency of ICE vehicles. They are exploring innovative combustion strategies, such as homogeneous charge compression ignition (HCCI) and stratified charge combustion, combined with turbocharging to improve power density and reduce fuel consumption.
    • Uniqueness of Research: TUM’s approach involves a holistic optimization of the engine system, including intake and exhaust systems, fuel injection strategies, and combustion chamber design. Their research integrates experimental testing with computational fluid dynamics (CFD) simulations to optimize the performance of downsized turbocharged engines under real-world driving conditions.
    • End-use Applications: The research at TUM has implications for the automotive industry, particularly in the development of more fuel-efficient and low-emission vehicles. Downsized turbocharged engines can be deployed in a wide range of vehicle types, including passenger cars, light-duty trucks, and commercial vehicles, to meet stringent emissions regulations while maintaining performance and drivability.
  • Aachen University:
    • Technology Enhancements: Aachen University researchers are focusing on innovative approaches to engine downsizing and turbocharging, such as variable geometry turbochargers (VGT) and electrically-assisted turbocharging systems. They are investigating the integration of electrification technologies, such as mild hybridization and waste heat recovery, to further enhance the efficiency and responsiveness of downsized engines.
    • Uniqueness of Research: Aachen University’s research emphasizes a systems-level optimization approach, considering the interactions between the engine, turbocharger, and auxiliary systems. They are developing advanced control algorithms and predictive models to maximize the benefits of engine downsizing and turbocharging while minimizing trade-offs in terms of emissions and drivability.
    • End-use Applications: The research at Aachen University has practical applications in the development of next-generation ICE vehicles, including hybrid powertrains and range-extended electric vehicles (REEV). Downsized turbocharged engines with integrated electrification technologies offer a viable transition pathway towards low-carbon mobility while leveraging existing infrastructure and manufacturing capabilities.
  • University of Michigan:
    • Technology Enhancements: University of Michigan researchers are exploring novel approaches to engine downsizing and turbocharging, such as advanced boosting systems and variable valve timing (VVT) technologies. They are investigating the use of alternative fuels, such as biofuels and synthetic fuels, to further reduce greenhouse gas emissions and enhance the sustainability of ICE vehicles.
    • Uniqueness of Research: The University of Michigan’s research integrates experimental testing with advanced modeling and simulation techniques to optimize the performance of downsized turbocharged engines across a wide range of operating conditions. They are exploring innovative combustion strategies, such as lean-burn and stratified charge combustion, to improve fuel efficiency and reduce emissions.
    • End-use Applications: The research at the University of Michigan has implications for both conventional and future ICE vehicles, including plug-in hybrid electric vehicles (PHEV) and hydrogen fuel cell vehicles. Downsized turbocharged engines offer a cost-effective solution for reducing vehicle emissions and improving fuel economy without compromising performance or range.

commercial_img Commercial Implementation

Engine downsizing and turbocharging are widely implemented in commercial vehicles across various segments, from small passenger cars to large trucks. Most major automotive manufacturers utilize these technologies to meet fuel efficiency standards and reduce emissions.