In an aggressive drive route that took an editor up into mountains, skirting 5,000 feet elevation at times, a test Elantra registered 26 mpg; then driven on a mostly level stretch of Interstate at 65-70 mph we managed to average 39 mpg—so at first test the Elantra's figure looks easily attained with the cruise control on a relatively level highway.
NOTE: The 2011-2013 Elantra lineup was found to have overstated fuel-economy numbers. Hyundai initially claimed up to 40 mpg highway for some models, but after a consumer campaign alleged lower real-world economy, the EPA ran a confirmation check of the Elantra lineup and of several other Hyundai and Kia vehicles. The tests resulted in restated fuel economy numbers for all involved model years. Owners can register with Hyundai to receive reimbursement for the gas consumed above and beyond expected levels; more details are found at HyundaiMPGInfo.com.