From Matthew Yglesias:
Q.:....But how are hybrids supposed to help us out of the global warming/foreign oil dependence trap when they are less efficient than a 24 year old non-hybrid beater? And why not just make cars like the aforesaid beater, with a hybrid engine in them?
A.:....Meanwhile, it's important to remember that for the short-run the most important thing isn't to develop futuristic new low-emissions vehicles. The low hanging fruit is to replace the very least efficient vehicles with more efficient ones. Replacing an SUV with a standard sedan does more to cut consumption than does replacing a sedan with a hybrid. Even replacing an SUV with a minivan brings about substantial reductions.