If fuel economy matters, and you're considering the 2012 Hyundai Elantra, there's no reason to go hunting around the dealership for the one vehicle that has a special package. All 2012 Elantras come with official EPA fuel economy ratings of 28 mpg city, 38 mpg highway. Considering that most of a vehicles lifetime carbon footprint is related to fuel use—and Hyundai is including things like aerodynamic tweaks and tall gearing on all cars, it makes the Elantra a very green model line.
There has been controversy and complaint over the Elantra's fuel-economy ratings. Many owners are finding they're unable to meet the 40-mpg highway numbers. In ordinary driving, we've noticed numbers that are in the same range as those of other vehicles in this class--about 34 mpg combined in an extended drive, exceeding the EPA Combined rating by 1 mpg. And we've seen close to the EPA highway rating in a real-world Interstate cruise.
The one major tradeoff for the diet that the Elantra was placed on, to optimize mileage, is that there's no spare tire--not even a porta-spare.
NOTE: The Elantra is one of several Hyundai vehicles found to have misstated gas-mileage ratings. A consumer group's complaints over lower real-world economy have led to an EPA check of Hyundai's self-certified numbers--which in turn has led to lowered official ratings from the original 29/40-mpg numbers. Owners can register with Hyundai to receive reimbursement for the gas consumed above and beyond expected levels; more details are found at HyundaiMPGInfo.com.