Dear Mr. Alson,
Today on the EPA web site I read about recent changes to the methods used to determine vehicle fuel consumption.
From
http://www.epa.gov/fueleconomy/
"Beginning with 2008 models, all fuel economy estimates [will be?] based on new test methods, which EPA finalized in December 2006. The new methods better account for actual driving conditions that can lower fuel economy, such as high speed, aggressive driving, use of air conditioning, and cold temperature operation."
I am interested in the reasoning behind the selection of the criteria specified above. After reading the 104 page EPA report, "Light-Duty Automotive Technology and Fuel Economy Trends: 1975 Through 2007", I was disappointed to find no mention of these criteria, other than in one paragraph of the Executive Summary.
It would seem that the EPA has decided that consumers will base comparative decisions on fuel economy around a scenario of "worst case".
Assuming that "cold temperature operation" is truly an important factor, what does the EPA think has changed or is about to change that warrants this special status.
Does the EPA believe that use of "air conditioning" is increasing? Or have air conditioners become less efficient? Why would air conditioning be a more important factor today if "cold temperature operation" is deemed significant.
Most importantly, "aggressive driving" and "higher speeds" - has the EPA thinking changed at all recently given the truly enormous increase in the price of oil that is currently finding its way through the supply chain and hitting the consumer hard in all aspects of their lives?