The Environmental Protection Agency has finalized new rules to determine U.S. vehicles' fuel efficiency, which will include estimates on the use of Mobile Air Conditioning and high speed driving.
Model year 2008 vehicles will be the first to receive the new miles per gallon (MPG) estimates for city and highway driving that appear on new vehicle window stickers. The future methods will reflect more realistic driving conditions by taking into account the use of air conditioning, high speed, rapid acceleration, and cold temperature operation.
Currently, the Environmental Protection Agency (EPA) relies on data from two laboratory tests under mild climate conditions to determine the city and highway fuel economy estimates. Neither test is run while using accessories. In the future, the performance of emission controls while the air conditioning system is operating is assessed via the so-called SC03 test. It will be performed in a test cell at 95°F and 40% relative humidity, with a solar load of 850 Watts per square meter on the vehicle.
EPA considers, that the future test methods will bring most vehicles' fuel efficiency rating for the city down by 12%, and the highway MPG estimates by 8% on average. This will require carmakers to further increase their vehicles' fuel economy.
To convey more effective information to the public, EPA has changed the window sticker's design and content. The new label will be required on vehicles manufactured after September, 2007.
Reactions
"EPA's new fuel economy sticker ensures American motorists won't be stuck with higher than anticipated charges at the pump," said EPA Administrator Stephen L. Johnson.
Next steps
In 2011, manufacturers will need to perform additional cold temperature, air conditioning, and/or high speed driving tests for those vehicles most sensitive to these conditions. The interim period from model year 2008 – when EPA's new fuel economy estimates will be applied - to 2011 will give manufacturers time to plan for this additional testing.
Background
EPA has been giving instructions on how to test vehicles, measure, calculate and report fuel economy since the 1970s. The current test methods for calculating fuel economy data were last revised in 1984. In 2002, the environmental group Bluewater Network initiated the process of revising these methods by sending a petition to EPA. After seeking public comment on this issue in mid-2006, EPA issued the new rules on 12 December.
