Gas mileage down but so are emissions, plus bonus gas price rollercoaster

Early this month, the University of Michigan reported Fuel economy in the U.S. drops from recent high.   Here's the complete press release.

ANN ARBOR—Fuel economy of new vehicles sold in the U.S. slipped last month for the first time this year, say researchers at the University of Michigan Transportation Research Institute.

Average fuel economy (window-sticker values) of cars, light trucks, minivans and SUVs purchased in April was 24.5 mpg, according to UMTRI researchers Michael Sivak and Brandon Schoettle.

"This value is down 0.1 mpg from the record high reached in March, likely reflecting the recent decrease in the price of gasoline," Sivak said. "Despite this small drop, the fuel economy is up 4.4 mpg since October 2007—the first month of our monitoring."

In addition to average fuel economy, Sivak and Schoettle issued their monthly update of their national Eco-Driving Index, which estimates the average monthly emissions generated by an individual U.S. driver. The EDI takes into account both the fuel used per distance driven and the amount of driving—the latter relying on data that are published with a two-month lag.

During February, the EDI improved to 0.82 from 0.83 the month before (the lower the value, the better). The index currently shows that emissions of greenhouse gases per driver of newly purchased vehicles are down 18 percent, overall, since October 2007.

While the average MPG of a new car is up slightly because of lower gas prices, the replacement of less fuel-efficient older vehicles with newer ones plus the fewer miles driven per person have reduced individual emissions.  That's good news, especially in the face of carbon dioxide at levels not seen since the Tertiary.

In related news, the corner station lost another skirmish in the ongoing price war.  As I reported last time:

Since then, the prices have gone up and down twice.  First, the corner station started another round of price raising and failed, as they posted prices of $3.89 two weeks ago.  The other stations didn't bite, and by the end of the week, everyone was selling for $3.65.  This week, the corner station charged out into No Man's Land again and managed to hold it until today.   On Monday, they were selling regular for $3.79 while the three stations down the street had prices of $3.75.  That lasted until this afternoon, when the three stations dropped regular down to $3.70.  By this evening, the corner station matched their price.  I can take comfort in competition working to keep prices down.

The next week, all the stations dropped their prices to $3.68.  Wednesday of last week, the corner station again charged out of their trench to do battle in No Man's Land, raising their price for regular to $3.89.  The stations down the block again held steady, so when I filled up, I did so at one of them.  By Friday, the corner station retreated back into their trench, lowering their price to $3.68.  I can again take comfort in competition working to keep my costs down.