While compact on the outside, it was listed by the United States Environmental Protection Agency as a mid-size car because of a spacious interior. Although the basic powertrain design had changed little since the second generation, fuel economy improved for Elantras with manual transmissions from an EPA city rating of to , and further to in 2006. Cars with automatic transmissions returned , a reduction of .Horsepower improved from 135 hp (100 kW) to 138 hp (102 kW), and torque from 132 to 136, mainly due to the addition of continuously variable valve timing (CVVT) in 2004. Originally, the horsepower rating was misrepresented as 140 hp (104 kW). In 2006, the Elantra was offered with a SULEV emission rated engine in some US states.