April Car & Driver: EPA changes in MPG calculations
#1
April Car & Driver: EPA changes in MPG calculations
In my April C/D, the lead article was interesting. In 2008 the EPA will change the way it calculates published EPA numbers. I can't find the article on the net yet (magazine just came out), but here are some interesting excerpts (article by Csaba Csere):
"The problem with the current mpg estimates is that they are based on the standard federal smog-emissions test (Federal Test Procedure 1975) for the city figure and the Highway Fuel Economy Test for the highway figure. These test cycles date back to the '60s and '70s. As a result, the city FTP75 has an average speed of 21.2 mph, uses a "cold" start of a balmy 75 degrees, and is conducted with the heating and air-conditioning system turned off and not drawing any power. Meanwhile, HFET calculations are derived at an average speed of 48.3 mpg and involve only mile accelerations-no harder than an 18-second 0-60 run."
The article linked the 412 page document describing the new test at: www.epa.gov/fueleconomy/fe-labeling-final-rule.pdf.
It goes on, "Hybrids will take the biggest hits. Measured by the new procedures, a 2007 Toyota Prius's city fuel economy woulddrop from 60 mpg to about 48. Its highway figure would shrink from 52 mpg to about 45."
The article said that most non-hybrids would take a 12% / 8% city/highway reduction respectively.
Interesting the new Prius numbers would seem to be closer to our database.
"The problem with the current mpg estimates is that they are based on the standard federal smog-emissions test (Federal Test Procedure 1975) for the city figure and the Highway Fuel Economy Test for the highway figure. These test cycles date back to the '60s and '70s. As a result, the city FTP75 has an average speed of 21.2 mph, uses a "cold" start of a balmy 75 degrees, and is conducted with the heating and air-conditioning system turned off and not drawing any power. Meanwhile, HFET calculations are derived at an average speed of 48.3 mpg and involve only mile accelerations-no harder than an 18-second 0-60 run."
The article linked the 412 page document describing the new test at: www.epa.gov/fueleconomy/fe-labeling-final-rule.pdf.
It goes on, "Hybrids will take the biggest hits. Measured by the new procedures, a 2007 Toyota Prius's city fuel economy woulddrop from 60 mpg to about 48. Its highway figure would shrink from 52 mpg to about 45."
The article said that most non-hybrids would take a 12% / 8% city/highway reduction respectively.
Interesting the new Prius numbers would seem to be closer to our database.
#2
Re: April Car & Driver: EPA changes in MPG calculations
The EPA has a web site that lets you look at the numbers:
http://www.fueleconomy.gov/feg/calculatorSelectYear.jsp
Although the article is technically correct, showing only the individual vehicle percent changes is misleading. The ratios between any two vehicles, the comparison function of EPA ratings, does not change as much as the "25%" hybrid change. For example, use the Chevy Aveo, CNW Marketing's Prius killer:
29 - old EPA, Aveo automatic
55 - old EPA, Prius automatic
189% Prius MPG is better than Aveo under old EPA
26 - new EPA, Aveo automatic
46 - new EPA, Prius automatic
177% Prius MPG is better than Aveo under new EPA
But in reality, the price of gas is the real determinant about buyer preference. So as the price of gas goes up, even the slightly reduced hybrid advantage will win, hands down.
Bob Wilson
http://www.fueleconomy.gov/feg/calculatorSelectYear.jsp
Although the article is technically correct, showing only the individual vehicle percent changes is misleading. The ratios between any two vehicles, the comparison function of EPA ratings, does not change as much as the "25%" hybrid change. For example, use the Chevy Aveo, CNW Marketing's Prius killer:
29 - old EPA, Aveo automatic
55 - old EPA, Prius automatic
189% Prius MPG is better than Aveo under old EPA
26 - new EPA, Aveo automatic
46 - new EPA, Prius automatic
177% Prius MPG is better than Aveo under new EPA
But in reality, the price of gas is the real determinant about buyer preference. So as the price of gas goes up, even the slightly reduced hybrid advantage will win, hands down.
Bob Wilson
#3
Re: April Car & Driver: EPA changes in MPG calculations
I've read on one article how hybrids are "the big loosers" and states the HCH dropped down to 42, while the regular Civic went to 29, and never even mentioning the spread.
Wonder if someones paying people to print these things?
Wonder if someones paying people to print these things?
#4
Re: April Car & Driver: EPA changes in MPG calculations
Now I average 3 mpg better than the highway mileage instead of 6 under. I still visit the gas pump twice a month and get twice the mpg of my old Escape or Cavalier. With the tax rebate, I still will break even in 18-20 months on the extra investment. Contrary to what CNW marketing says or the EPA numbers imply, I'm ahead of the ball in terms of $$$ and environmental responsibility.
#5
Re: April Car & Driver: EPA changes in MPG calculations
The new EPA ratings for my HAH seem to be pretty close to what I've been getting. I wish they changed their testing procedures years ago!
#6
Re: April Car & Driver: EPA changes in MPG calculations
I've almost always gotten 42 MPG out of my Civic Hybrid. At least now I know it's the mileagei t's supposed to get!
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