The ION is available as a four-door sedan or an innovative coupe, which Saturn calls a Quad Coupe for its unusual reverse-opening rear doors. The base engine for the Ion is a 2.2-liter four-cylinder rated at 140 horsepower. New for 2006 is a 2.4-liter four-cylinder rated 170 horsepower. The top-performing Red Line model comes with a supercharged 2.0-liter four rated 205 horsepower. A five-speed manual transmission is standard, and an automatic transmission is optional. The sedan is offered in two trim levels, called Ion 2 and Ion 3. Quad Coupes come in Ion 2, Ion 3, and Red Line trim.For 2006, the Saturn ION receives some styling, package, and trim changes. It also makes a more powerful engine available.