From the 1996 Survey of Consumer Attitudes (n=400 or so):
On average, about how many miles per gallon of gas would you expect to get on the next vehicle that (you/your family) would purchase?
- Average = 24
If the vehicle got ten percent better fuel economy than the (Average = 24) miles per gallon you now expect, how much extra would you be willing to pay for the vehicle?
- Average = 0.81%
- 88% would pay zero
- The average for those who would pay something is 6.82%
Even considering the incentive to say 0% if you don't have a good answer in mind or if you don't want to reveal your willingness to pay to someone who might turn out to be a car salesperson, that 88% is strikingly high.
67% of these respondents thought that the price of gas would go up during the next five years. The average expected price increase was $0.23. The price of a gallon of regular gasoline in March 1996 was $1.48 (2006 dollars); in March 2001 it was $1.64.
So there ya go.
Update: The undiscounted cost savings over 100k miles of a 10% improvement in MPG is $568. This is almost 4% of a $15,000 auto. Calculations:
Miles 100,000 100,000 MPG 24 26.4 Gallons 4167 3788 Price $1.50 $1.50 Cost $6,250 $5,682