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Internal Combustion Engine for On-Road Commercial Powertrains

With more than 60 years' experience in engine development with particular focus on engine development for commercial vehicles, AVL is the right partner for all development activities creating a new, upgraded or improved engine. All this experience shows direct advantage in every single customer project to quickly find the optimum solution tailored to every customer's different requirements AVL has developed unique tools for the development of engines in the complete Powertrain, to optimize the interaction between the different Powertrain systems.

AVL Solution

  • New engine developments for On-road engines as well as upgrades or smaller improvements
  • Alternative fuel engine development as e.g. Gas engines
  • Fuel efficiency improvement activities
  • Optimizing the interaction of the engine in the complete Powertrain.
  • Engine Portfolio consulting
  • Application variant development
  • All engineering activities as design and simulation, calibration, acoustic engineering up to benchmarking.

AVL Approach

To analyze the dedicated Application and its variants by system engineering means to really tailor the final technical solution for the engine to develop. AVL own tools as AVL Cruise ensure the correct and professional analysis of the surrounding environment to the engine (vehicle, driving cycle, etc.)

The unique AVL tool chain consists of smart simulation applications covering all needed areas to guarantee an efficient development process.

Fuel efficiency measures for the next generation of engines with an attractive Return On Investment (ROI)

While the pace of implementing more stringent emission legislations in the Triad markets has been reduced, the challenge for the coming years will be to offer more Fuel efficient products and reduce product cost.

AVL has several ongoing R&D programs addressing different measures to accomplish the absolute best solution for our customers.

One of the key technologies for further optimized engines fulfilling stringent emission legislations will be the charging system.
Figure 1 shows the potential of advanced charging technologies at a typical road load point for a HD long haul truck application. At constant excess-air ratio a turbocharger efficiency increase of 5% would result in a BSFC benefit of approximately 1%. Additionally the engine high pressure cycle can be improved by increased excess-air ratio (higher cylinder charge mass). Considering this increase in excess-air ratio the BSFC level could be reduced by even 1.5%.

Figure 1: Fuel consumption depending on turbocharger efficiency and excess-air ratio at a typical road load point for a HD on road application (1200rpm, BMEP 12bar).
Turbochargers with such improved efficiencies are currently in development at the turbocharger suppliers and will be available on the market for series production soon.
Assuming an increase in turbocharger efficiency by 10% - such highly efficient
turbochargers could be available on the market long term - would even lead to a fuel
consumption benefit up to 3% for a standard European long haul truck.

Increasing turbocharger efficiency will challenge the EGR systems significantly.
Since the positive pressure difference between intake and exhaust manifold will further increase, the achievable EGR rates will drop consequently (see Figure 2). Therefore a standard high pressure EGR system may reach its functional limits.

Figure 2: Pressure difference between intake and exhaust manifold depending on turbocharger efficiency levels and excess-air ratio for a HD on road application (1200rpm, BMEP 12bar).
However, as long as reduced EGR rates and the consequent increase of engine out NOx levels can be managed by the applied SCR system, the conventional high pressure EGR system can be kept. In case the EGR rates would drop to an insufficient low level alternative EGR concepts would be necessary to be introduced for such high efficient turbocharging systems.

AVL has been working successfully on alternative EGR concepts (turbo compounding, low pressure EGR, etc.) which provide the required EGR rates in combination with a positive pressure difference between intake and exhaust manifold.

A well understood principle to gain Fuel economy is downsizing and downspeeding. Both principles take advantage of better specific Fuel consumption at higher engine load. The potential depends on the different fuel consumption in different load points and can be significant. Depending on the downspeeded range the concept requires advanced transmissions as DCT (Doubble clutch transmissions) to utilize the real potential. AVL has developed a DCT concept and has all tools and methods to be able to develop a downspeeded Powertrain.

Another area for a potential Fuel efficiency gain is Thermal Management. Auxiliaries on demand in combination with intelligent control strategies can adapt the generated cooling power to the needed one. Incorporation of predictive control can maximize the fuel efficiency gain. AVL is developing control strategies for this approach on a modular basis to enable tailored solutions for every customer's need.
Squeezing out most of the generated heat would be to utilize the heat in the exhaust by a Waste heat recovery system (WHR). AVL has worked extensively with this topic and the different configurations and principles. With mature technology and components the ROI  < 2 years can be reached.  Mild hybrid concepts as electrified auxiliaries in combination with a WHR concept generating electric energy would take the total energy efficiency to another level.

Despite all new fuel efficiency measures well-known ones as e.g. friction reduction should not be forgotten. Friction losses count for a significant part of the total losses in an internal combustion engine and still show potential for reduction.
AVL has innovative solutions for base engine design aimed for friction reduction as well as unique methodologies for friction analyzis.
AVL's unique floating liner concept allows studying the contribution of single components in the piston – liner – conrod system which can't be managed by traditional strip down methods.
AVL has also developed a methodology which makes it possible to analyze the interaction of friction and wear to identify areas of independence.

Cost conscience has become very important in the whole automotive industry particularly in the Commercial vehicle business. Product cost and Total cost of ownership (TCO) are more important than ever. Development efficiency is a key focused area for most OEM.

The significant step in reduced emissions the last 10 years has led to the implementation of costly Engine Aftertreatment Systems. AVL has developed methods to allow a significant reduction of the EATS product cost by means of advanced emission models as well as the development of more efficient EAS coatings.

AVL's model based calibration tool (MobEO) is a well proven tool to cut development time and avoid expensive iterations with physical hardware (engines, EAS). Link to MobEO and calibration.
Another very valuable tool to reduce Development time and cost is an efficient validation method. AVL has developed the unique load matrix approach which helps to tailor the validation for the intended application.

Market Requirements

The internal combustion engine will continue playing a major role in future commercial powertrains particularly in Heavy duty long haul applications while alternative Powertrain systems as full Hybrids will play a more important role for Light duty applications but also for city busses in the future. Nevertheless micro- and mild hybrids will also enter into the commercial vehicle long haul world.







Alternative fuel concepts as Gas engines will become more important for all engine sizes mainly due to the beneficial fuel prize.

While the pace of implementing more stringent emission legislations in the Triad markets has been reduced, the challenge for the coming years will be to offer more Fuel efficient products and reduce product cost.

AVL has several ongoing R&D programs addressing different measures to accomplish the absolute best solution for our customers.

Customer Benefits

  • Global market overview of the diverse requirements for different markets and applications
  • Access to a global network of well experienced and competent engineering resources and well equipped facilities
  • Access to a wide range of top technologies developed by AVL for your new or upgraded commercial engine
  • Use of AVL's extensive technical and market experience to investigate the future potential of your engine portfolio
  • Tailored solutions to every customer's specific requirements, enabling to position the customer's product on the market according exactly to the customer's strategy and product plan
  • Working with a partner who can optimize your engine in the complete Powertrain for its optimal application


Over 120 significant commercial engine projects in the last 5 years

  •     AVL is working globally, for all significant manufacturers in the on-road and off-road industry
  •     AVL designs & develops several new engines and engine families every year
  •     Projects scope:

-> from concept to vehicle integration and production


  •     New engine families for developed and emerging markets
  •     Emissions development for EU6 & Tier 4 / Stage 4
  •     High efficiency SCR systems to meet Tier 4 w/o DPF and EGR (>56kW)
  •     Production SW and controls (engine + EAS) for Tier 4
  •     Model based engine calibration via system modeling (HiL development)
  •     Validation planning and optimization for EU6 & Tier 4
  •     Cost reduction programs & localization support for emerging markets