The 2014 Honda CR-Z with the continuously variable transmission (CVT) gets a reasonable EPA combined rating of 37 mpg (36 mpg city, 39 mpg highway). For our money, the version with the six-speed manual gearbox--the only one fitted to any hybrid sold in the U.S.--is more rewarding to drive, but you'll pay the price in fuel efficiency. Its ratings drop to 34 mpg (31 mpg city, 38 mpg highway). And these are some of the lowest ratings for any hybrid this small.
So while the CR-Z gets good fuel economy, you give up a lot--including a rear seat--to get it. There are any number of hybrids that are larger and more capacious that outdo the littlest Honda on fuel efficiency too, including three different models of the Toyota Prius--and even the new Mitsubishi Mirage, which does without a hybrid. The Toyota Prius C subcompact, for instance, gets a combined 50-mpg rating, and even Honda's own Insight--like the Prius C, a five-door subcompact hatchback--is rated at 42 mpg combined.
Moreover, the CR-Z's mild hybrid system doesn't offer the allure of all-electric running, unlike any of those Prius models. Nor is the fun, sporty coupe that its CRX antecedent was. So you've given up two seats and most of your luggage volume for a car that doesn't really deliver on its sporty appearance. To put the CR-Z at the top of your shopping list, you really have to want a very small two-seat hatchback that also gets 34 to 37 mpg.