an economical 1.8 L 4-cylinder 140 hp 1ZZ-FE engine and the ZZT231 powered by a higher-performance 1.8 L 4-cylinder 181 hp 2ZZ-GE version, co-developed with Yamaha . Both of these engines featured Toyota's signature VVT-i (Variable Valve Timing with Intelligence) system, which continuously varies the camshaft timing. For 2003 model year,