Statistically Speaking: Cash for Clunkers Wrap-Up

Update - 9/11/2009: The federal government’s Cash for Clunkers program (officially called the Car Allowance Rebate System) traded a total of 690,114, just short of our estimate of 720,000.

The final mileage difference between the scrapped clunkers and the new cars was was 9.1 miles per gallon (0.5 mpg down from the initial estimate of 9.6 mpg) and the final price tag was $2.877 billion (about $123 million off the $3 billion estimate).

Adjusting for these differences, the actual gasoline and carbon savings were a bit smaller than our estimates below. However, due to rounding, only one stat changed: instead of our estimated 1.6 million metric tons saved, CO2 emissions savings were actually 1.5 million metric tons.

With the Cash for Clunkers program scheduled to end on Monday, here’s a sneak peek of its net impact on the nation’s fuel consumption and carbon dioxide emissions.

A couple of the key climate objectives of this program were to

• Reduce our dependence on foreign oil, and 
• Lower U.S. emissions of pollutants, including carbon dioxide (CO2)

by getting gas guzzlers off the road and replacing them with more fuel efficient cars.  So how did the program fare? Was it worth it? Here are some preliminary numbers.
 

Cash for Clunkers: How Many Gallons of Gasoline? How Many Tons of CO2

Estimated number of gallons of gasoline saved as a result of the program:  0.2 billion gallons/year*

Estimated drop in U.S. CO2 emissions as a result of the program: 1.6 million metric tons CO2/year**

Direct cost to federal government of the Cash for Clunkers program:  $3 billion
 

Better Than Program to Get Tires Properly Inflated?

Estimated number of gallons of gasoline saved if all cars in US had their tires properly inflated [pdf]: 1.2 billion gallons/year

Estimated reduction in U.S. CO2 emissions if all cars in US had their tires properly inflated: 10.9 million metric tons CO2/year

Direct cost to federal government to properly inflate car tires: $0

Notes:
* Assumes a projection of 720,000 cars sold based on CARS data released on August 20, 2009. Also uses the average fuel economy differential announced on August 3, 2009, (clunker with 15.8 mpg to new car with 25.4 mpg) and 13,000 miles driven annually. 
** Total CO2 saved from using less gasoline accounting for CO2 embedded in new car.

This post has been revised to reflect the following correction:
Correction: September 11, 2009
As originally published, we mistakenly listed the estimated drop in U.S. CO2 emissions as a result of the program at 1 million metric tons CO2/year. This should have been 1.6 million metric tons CO2/year.