- The Lexus RX 450 was launched in 2010. It was powered by a 3.5-liter six-cylinder engine capable of producing 295 horsepower. The only change to the 2011 model year was the discontinuation of the Sports package. No major changes were made for 2012. In 2013, Lexus updated the RX 450h with a new grille and made minor other cosmetic tweaks. The carmaker also added a powered liftgate and iPod/UBS interface standard. Subtle changes were made to the steering and transmission systems, too. The 2014 model year featured the addition of a 115-volt power socket in the rear, and a new collision warning system. An optional iPhone integration feature was also introduced.