Sixteen miles per gallon, to twentyfive

For every driver who's replaced a car getting 16 miles per gallon with one getting 25 miles per gallon there's a saving. As Paul Krugman noted a month or three ago, it's much better to deal with the inverse quantity, so let's do this: let's compute gallons per hundred miles: the more efficient car uses about 4 gallons versus 6 plus change for the clunker.
Now, I don't drive very much in my car, but let's use my mileage as a guideline: I put between 5,000 and 10,000 miles on my car in a year. Let's call it 8,000. So in a year, a driver switching cars would use about 160 fewer gallons of gas,
Now, the original "Cash for clunkers" program was about $1 billion: this means that about 250,000 cars have been replaced. Assuming that drivers drive about the same distance, that means around 40 million few gallons of gas will be used in the next 12 months. I suspect that I've probably underestimated the mileage of the average participant --- there's a bigger extra incentive for someone who drives a good deal more than me to switch than there is for someone with my mileage.
If the extra $2 billion program goes through, and if I'm off by a factor, say, of 2.5 on the miles, we could be talking about 300 million gallons of gas saved: a drop in the bucket in terms of total gas consumption, it's true, but still not to be sneezed at. It should be pointed out too, that this represents an additional savings to those who participate of a little less than $1 billion -- the cost of the first third of the program.

Yours, getting some mileage from this one,
N.