Absolutely not. A few things to consider, after recently buying a car that we average a bit over 40 mpg with:
– The most fuel efficient car we looked at was the least expensive. You could turn it into a plug-in hybrid, get it rated at 60 mpg or better, and still be competitive with the prices of other small sedans.
– The 40+ mpg Ford we have now has greater acceleration than a Ford Mustang from the 1960s (2011 Ford Fiesta 1.6L I4 with auto transmission: 0-60 in 9.5 seconds – 1966 Ford Mustang V8 with auto transmission: 0-60 in 10.9 seconds). Invest advances into better mileage instead of greater performance that isn't actually necessary and you'd see a big increase in mileage.
– Gas prices aren't going to be going down in the next decade and a half. Maybe it won't be $10/gallon in 2025 but it will be high enough that people would be willing to pay a reasonable premium to double their gas mileage.
– Hybrids are already coming down in price as the technology matures. Plug-ins will do the same. There is still a significant premium because the technology is new. Give the technology time to mature and the makers time to make plug-ins a significant segment of the market and you'll see those prices come down.