Oil Shocks: Will $4 a gallon gas put us in four-cylinder Kias?

Amazingly enough, $3 a gallon gasoline has not yet had much impact on the way Americans drive. Although there have been some defections from the larger SUVs, and lip service to such alternatives as public transit and car pools, the U.S. remains a country on the move, with the highest vehicle miles traveled (VMT) in the world.

What will it take, exactly? The latest Middle East turmoil is doing a number on oil prices, which have reached as high as $78 a barrel and may soon hit $100, which would send prices as high as $4 a gallon. When Goldman Sachs predicted this some months ago the general impression was that the firm was off its nut.

According to respected and Texas-based oil analyst Matthew Simmons, quoted in the Observer ,