“The new car doesn’t replace the clunker, it replaces the previous first car in the family,” said Lee Schipper, a transportation expert and researcher at the University of California, Berkeley, and at Stanford University.

“The new car doesn’t replace the clunker, it replaces the previous first car in the family,” said Lee Schipper, a transportation expert and researcher at the University of California, Berkeley, and at Stanford University.

“There’s no real way to calculate it without making a bunch of assumptions,” said Lee Schipper, a researcher at the University of California, Berkeley, and at Stanford.

“There’s no real way to calculate it without making a bunch of assumptions,” said Lee Schipper, a researcher at the University of California, Berkeley, and at Stanford.

Transportation expert Lee Schipper of Stanford University and the University of California at Berkeley, said, "The new car doesn't replace the clunker, it replaces the previous first car in the family."

Transportation expert Lee Schipper of Stanford University and the University of California at Berkeley, said, "The new car doesn't replace the clunker, it replaces the previous first car in the family."

If you think the Cash for Clunkers program is confusing for dealers and buyers, you should try figuring out its impact on fuel use or carbon emissions. Despite the environmental accolades showered on the program, its environmental effects will be negligible.

If you think the Cash for Clunkers program is confusing for dealers and buyers, you should try figuring out its impact on fuel use or carbon emissions. Despite the environmental accolades showered on the program, its environmental effects will be negligible.

In terms of the average fuel economy of the entire fleet, the Cash for Clunkers program is hardly even measurable. With 254 million registered vehicles in the U.S., the fact that 250,000 new cars are more efficient is a mere blip.

In terms of the average fuel economy of the entire fleet, the Cash for Clunkers program is hardly even measurable. With 254 million registered vehicles in the U.S., the fact that 250,000 new cars are more efficient is a mere blip.