Base engine was a 3.4-liter V6 (an enlargement of the former 3.1-liter), delivering 160 horsepower. Either 5-speed manual shift or a 4-speed overdrive automatic might be installed. Under the Z28's hood lurks a Corvette-based 5.7-liter V8 rated at 275 horsepower (285 horses for '96) and hooked to a 6-speed manual gearbox or optional 4-speed automatic. Unlike the Corvette's drivetrain, the Z28's 6-speed box lacked a forced first-to-fourth gear shift under light throttle in its first season, but added that fuel-economy feature for '94, when the automatic shift gained electronic control. Six-speed cars also got a 3.42:1 rear-axle ratio in 1994, replacing the prior 2.73:1 or optional 3.23:1 ratio. A more powerful (200-horsepower) 3.8-liter V6 arrived in spring 1995 as an option, and was made standard for '96. Engines in specially built SS Camaros in 1996 developed 305 horsepower--20 more than usual. In 1998, Camaro got its own version of the Corvette V8. In Z28, trip the engine made 305 horsepower. With the SS package it made 320 horsepower. V8s gained 5 horsepower in 2001.