Pop the redesigned Hyundai Elantra's hood and under the handsome plastic shroud is an upgraded version of the 2.0-liter four-cylinder engine from the previous model. Engine upgrades result in better fuel economy of 28 mpg in the city and 36 mpg on the highway regardless of transmission choice. In California and New England, the Elantra is rated as a Partial Zero Emissions Vehicle (PZEV) when the engine is equipped with the optional automatic transmission.