The 2.0-liter four-cylinder in the Mazda3 i has variable valve timing and develops 148 horsepower (144 hp in PZEV form). The Mazda3 s uses a 2.3-liter four-cylinder that pumps out 156 hp. A five-speed manual gearbox is standard, and a four-speed automatic transmission with a manual-shift provision is optional for the Mazda3 i. The 2.3-liter engine can mate with a five-speed automatic.