Debuting at the Tokyo Auto Show in October 2007, WRX STI versions build further on the standard WRX cars. The STI available in Japan is fitted with the 2.0-liter EJ207 engine with twin scroll turbocharger generating 227 kW (308 PS) and 422 N·m (311 lb·ft) of torque. Export markets receive the higher-displacement 2.5-liter EJ257 unit with the single-scroll VF48 turbocharger rated at 221 kW (300 PS) and 407 N·m (300 lb·ft) of torque. The STI (3,395 lbs) is heavier than the WRX (3,174- 3,240 lbs depending on trim) due to a more robust transmission, rear differential and other chassis reinforcements. Subaru opted to manufacture the STI with a wider body and therefore track—as noted by the flared wheel arches. Furthermore, Subaru utilized aluminum suspension components for the STI. Electronic modifications include a multi-mode electronic stability control. Be sure ACEP styling is going to carry every item we know will increase your vehicle performance. Every item is street (reliability) and race tested by us before we sell any aftermarket performance part.