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Reducing the Fuel Consumption and Greenhouse Gas Emissions of Medium- and Heavy-Duty Vehicles, Phase Two First Report (2014) / Chapter Skim
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2 Potential for Technological Change in Commercial Vehicles to Impact Future NHTSA Regulations
Pages 23-28

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From page 23...
... in the years before and during the pumps; explore engine friction reduction; explore Phase II regulations' time frame. The work scope has the downsizing or downspeeding options, including higher following tasks: Task 1: program management; Task 2: lit peak cylinder pressure if needed; possible upsized vererature review and summary tables; Task 3: augment under sion for lower Class 8 applications; explore reactivity standing of MY11+ vehicle fleet baseline (engines compliant controlled compression ignition with information with 2010 EPA regulations)
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From page 24...
... Although final results from these tasks are still pending, it is anticipated that this study will refine and supplement Recommendation 2.2:  NHTSA's Phase II Rule should the NRC Phase One Report findings and recommendations take the current and projected incremental fuel consumption regarding power train and vehicle technologies as summa- reductions and penetration rates of the various technologies rized in Figure 6-1 and Tables 6-18 and 6-19 of the Phase into careful consideration: These incremental reductions One Report. and penetration rates should be updated from those that The projections in Figure 6-1 and Tables 6-18 and 6-19 of were projected in the Phase I rulemaking.
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From page 25...
... In combination with advanced fric Among the new engine and vehicle technologies that have tion modifiers and viscosity improver additives, this been introduced since the Phase One Report, the emergence could provide additional fuel efficiency. The amount of of natural gas as a transportation fuel is of significance.
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From page 26...
... Allison expansion ratio, combustion chamber architecture, has introduced a new 10-speed automatic transmis injection timing, injection pressure, rate shaping, air: sion with a measured improvement in fuel economy fuel ratio control, air/fuel mixing, etc. All these mea- compared to manual and AMT transmissions in Class sures contribute to a higher combustion temperature, 8 day cab vehicles.
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From page 27...
... Fleets generally recycle partially worn tires by moving them from drive axles to the trailer, resulting in a less than optimum total vehicle package. VEHICLE TECHNOLOGY WBSTs provide a weight saving compared with dual tires The following technologies involving the other compo- of about 340 kg per five-axle combination tractor-trailer nents of the vehicle are addressed by the OEMs as identified rig.
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From page 28...
... 2009. Assessment of Fuel Economy Technologies for Medium- and Heavy-Duty Vehicles.
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Key Terms

  • fuel efficiency
  • fuel economy
  • nrc phase
  • rolling resistance
  • variable valve

  • engine friction
  • various technologies
  • duty cycle
  • ghg emissions
  • compression ignition

  • additional fuel
  • explore variable
  • vehicle technologies
  • tire failure
  • power train

  • natural gas
  • percent fuel
  • explore engine
  • thermal efficiency
  • national highway

  • charge compression
  • lower viscosity
  • technology penetrations
  • parasitic power
  • emission control

  • diesel exhaust
  • regulatory impact
  • consumption reduction
  • power steering
  • simulation modeling


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