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The air-conditioning (A/C) compressor load significantly impacts the fuel economy of conventional vehicles and the fuel use/range of plug-in hybrid electric vehicles (PHEV). A National Renewable Energy Laboratory (NREL) vehicle performance analysis shows the operation of the air conditioner reduces the charge depletion range of a 40-mile range PHEV from 18% to 30% in a worst case hot environment. Designing for air conditioning electrical loads impacts PHEV and electric vehicle (EV) energy storage system size and cost. While automobile manufacturers have climate control procedures to assess A/C performance, and the U.S. EPA has the SCO3 drive cycle to measure indirect A/C emissions, there is no automotive industry consensus on a vehicle level A/C fuel use test procedure. With increasing attention on A/C fuel use due to increased regulatory activities and the development of PHEVs and EVs, a test procedure is needed to accurately assess the impact of climate control loads.

The energy used to air condition an automobile has a significant effect on vehicle fuel economy and tailpipe emissions. If a small reduction in energy use can be applied to many vehicles, the impact on national fuel consumption could be significant. The SCO3 is a new emissions test conducted with the air conditioner (A/C) operating that is part of the Supplemental Federal Test Procedure (SFTP). With the 100% phase-in of the SFTP in 2004 for passenger cars and light light-duty trucks, there is additional motivation to reduce the size of the A/C system. The U.S. Department of Energy's National Renewable Energy Laboratory (NREL) is investigating ways to reduce the amount of energy consumed for automobile climate control. If the peak soak temperature in an automobile can be reduced, the power consumed by the air conditioner may be decreased while passenger comfort is maintained or enhanced. Solar reflective glass is one way to reduce the peak soak temperature.

Today's advanced-technology vehicles (ATVs) feature hybrid-electric engines, regenerative braking, advanced electric drive motors and batteries, and eventually fuel cell engines. There is considerable environmental and regulatory pressure on fleets to adopt these vehicles, resulting in high-risk purchase decisions on vehicles that do not have documented performance histories. The Department of Energy's Field Operations Program tests ATVs and disseminates the results to provide accurate and unbiased information on vehicle performance (http://ev.inel.gov/fop). Enhancing the fleet manager's knowledge base increases the likelihood that ATVs will be successfully and optimally placed into fleet missions. The ATVs are tested using one or more methods - Baseline Performance, Accelerated Reliability, and Fleet Testing. The Program and its 10 testing partners have tested over three-dozen electric and hybrid electric vehicle models, accumulating over 4 million miles of testing experience.

A turbocharged lean burn natural gas engine was upgraded to operate on a blend of hydrogen and natural gas (HCNG). Tests were carried out to determine the most suitable H2/NG blend for H2 fractions between 20 and 32 vol%. A 20 vol% H2 content was found to provide the desired benefits when taking into consideration the engine and vehicle performance attributes. A full engine map was developed for the chosen mixture, and was verified over the steady-state AVL8 cycle. In general, the HCNG calibration included operation at higher air-fuel ratios and retarded spark timings. The results indicated that the NOx and NMHC emissions were reduced by 50% and 58% respectively, while the CO and CH4 emissions were slightly reduced. The HCNG engine torque, power and fuel consumption were maintained the same as for the natural gas fuel. The chassis dynamometer transient testing confirmed large NOx reduction of about 56% for HCNG operation.

The U.S. Department of Energy (DOE), Office of Heavy Vehicle Technologies (OHVT) is promoting the use of natural gas as a fuel option in the transportation energy sector through its natural gas vehicle program [1]. The goal of this program is to eliminate the technical and cost barriers associated with displacing imported petroleum. This is achieved by supporting research and development in technologies that reduce manufacturing costs, reduce emissions, and improve vehicle performance and consumer acceptance for natural gas fueled vehicles. In collaboration with Brookhaven National Laboratory, projects are currently being pursued in (1) liquefied natural gas production from unconventional sources, (2) onboard natural gas storage (adsorbent, compressed, and liquefied), (3) natural gas delivery systems for both onboard the vehicle and the refueling station, and (4) regional and enduse strategies.

Fuel consumption (FC) has always been an important factor in vehicle cost. With the advent of electronically controlled engines, the controller area network (CAN) broadcasts information about engine and vehicle performance, including fuel use. However, the accuracy of the FC estimates is uncertain. In this study, the researchers first compared CAN-broadcasted FC against physically measured fuel use for three different types of trucks, which revealed the inaccuracies of CAN-broadcast fueling estimates. To match precise gravimetric fuel-scale measurements, polynomial models were developed to correct the CAN-broadcasted FC. Lastly, the robustness testing of the correction models was performed. The training cycles in this section included a variety of drive characteristics, such as high speed, acceleration, idling, and deceleration. The mean relative differences were reduced noticeably.