Audi's A4 compact-class sedans and avant wagons emerged in 2002 with new generational designs that expanded the structure and stretches the wheelbase to forge a larger package with more cabin space for riders. Entry issue in the A4 series is the 1.8T sedan with a 1.8-liter turbo plant in FrontTrak format linked to a manual five-speed gearbox. In addition, Audi offers its multitronic shifter, a continuously variable transmission (CVT) that approaches the manual's fuel economy and quickness but delivers undetectable shift transitions through an electric clutch. To ensure tire traction on pavement, A4 1.8T is also available with Audi's quattro system, a permanently engaged device that distributes the engine's power to all wheels. Audi also casts A4 in luxury mode as the A4 3.0 sedan and avant wagon. These versions are fired by an aluminum-block 3.0-liter V6 that generates 220 hp. A4 3.0 quattro gets either a manual six-speed or five-speed Tiptronic automatic. The new A4 3.0 Cabriolet, an airy drop-top rigged with power-operated retractable top covered in cloth and etched with a heated rear window, also draws from the 3.0-liter V6 and provides extensive safety gear, including side-impact air bags and ARPS. Power controls for the driver's seat are available on the 1.8T sedan and 17-inch all season tires show up optionally with A4 3.0 Cabriolet.