Heavy-Duty Vehicle
Emissions Evaluations
Office of Automotive Engineering

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image: HD trucks and buses can be operated through simulated driving cycles while measuring exhaust emissions and fuel consumption.

HD trucks and buses can be operated through simulated driving cycles while measuring exhaust emissions and fuel consumption.

Heavy-duty vehicle chassis evaluations are performed using a 48-inch twin-roll chassis dynamometer. The dynamometer has the ability to simulate vehicle weights up to 120,000 pounds for tandem axle vehicles and 60,000 pounds for single-axle vehicles at a maximum of 600 horsepower. It is equipped with an electric motor drive for each roll that may operate to test single-axle, tandem-axle, or four-wheel drive vehicles.

In addition to steady-state testing, transient tests can be performed that simulate road load, vehicle inertia, and road grade. This allows simulation of in-service vehicle operation.

Dynamometer Test Area

The dynamometer test area includes temperature control and is equipped with a 300-horsepower fan capable of simulating wind speeds up to 100 miles per hour. The room accommodates vehicles up to 14 feet. high by 14 feet wide by 60 feet. long with wheelbases up to 45 feet for single- or tandem-axle vehicles, and from 4 feet to 20 feet for four-wheel drive vehicles. The facility is ideal for testing heavy-duty hybrid electric vehicles (HEVs).

Exhaust emissions measurement is CFR Title 40 Part 86, Subpart N and Part 1065 compliant and includes a full-scale constant volume sampling (CVS) system. Measurements include:

  • Total hydrocarbons
  • Oxides of nitrogen
  • Particulate matter
  • Carbon monoxide
  • Carbon dioxide
  • Fuel consumption
  • Individual hydrocarbon species
  • Particulate matter composition

Please also see the additional related information:

Related Terminology

computer-aided engineering  •  CAE  •  design analysis  •  computer-aided analysis  •  CAA  •  computer-aided design  •  CAD  •  computational fluid dynamics  •  CFD  •  cycle simulation  •  finite element analysis  •  FEA  •  kinematics  •  design  •  modeling  •  design process  •  engineering models  •  noise, vibration and harshness  •  NVH

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Southwest Research Institute® (SwRI®), headquartered in San Antonio, Texas, is a multidisciplinary, independent, nonprofit, applied engineering and physical sciences research and development organization with 9 technical divisions.