Sure, if cars were more fuel-efficient, we might use less oil, but so what?
I've heard liberals like Bill Maher whining ever since 9/11 that if we weren't addicted to oil from the middle east that we wouldn't have to fight wars for oil.
The fact of the matter is that very little of the oil we import comes from the middle east. Of the oil we import, only 12% comes from Saudi Arabia, 5.8% comes from Iraq, and 1.8% comes from Kuwait. These are the 2001 numbers from [url]http://www.ita.doc.gov/td/industry/otea/usfth/aggregate/H01t33.pdf[/url].
So we can do without Middle East oil.
Unfortunately, Europe and Japan are far more dependent on Middle East oil than we are. ...and since the value of trade between the US and Europe is something like $2 trillion per year, anything that hurts the European or Japanese economies ultimately hurts ours.
So if you're getting at the question of how do we insulate ourselves from problems related to foreign oil, we're essentially doing everything we can reasonably be expected to do.
Bush's plan to increase domestic production and create incentives for the development of more efficient products is a wise move looking forward.