The high-performance version of Cadillac's retractable hardtop convertible, the XLR-V made its debut in 2006. A vehicle based on a fifth-generation Chevrolet Corvette, the Cadillac XLR-V's sport tuning adds a considerable punch to the personal luxury car. Instead of a 4.6-liter Northstar V-8, the XLR-V finds momentum from a supercharged 4.4-liter V-8 engine. Producing 443 horsepower, the Cadillac XLR-V touts a 123-horsepower upgrade over the conventional XLR. Aside from engine power, other enhancements employed on the V-Series version of the XLR include a stiffer suspension featuring Magnetic Ride Control, enlarged braking discs and Pirelli tires mounted to 19-inch alloy wheels. The six-speed automatic transmission introduced on the 2006 XLR-V was adopted by the conventional Cadillac XLR in 2007. Changes to the Cadillac XLR-V were minor for 2007 and 2008. In the car's final production year in 2009, styling was mildly revised and an Alcantara headliner was added.