The XRS trim included an engine upgrade to Toyota's higher-performance 2ZZ-GE engine. Displacing , or 109.6 cubic inches, it produced and – a then-rare 100 horsepower-per-liter. While its 11.5:1 compression ratio was a large factor in its performance, the engine could change to a second cam profile at higher RPM through Toyota's VVTL-i and was designed for operation up to 8500 RPM. The engine's high compression necessitates "premium" gasoline (91 octane or above in the (R+M)/2 scale). With the exception of an available automatic in 2003, a six-speed manual transmission was the only gearbox offered in the XRS. A Transitional Low Emission Vehicle (TLEV) its first year of production, the 2ZZ was retrofitted in 2004 with a smog pump and reclassified as an Ultra Low Emission Vehicle (ULEV).