The Acura RDX is a compact luxury crossover SUV produced by Acura, a luxury vehicle division of Honda, as the second crossover SUV offering from the brand after the mid-size MDX. Initially sharing its platform with the Honda Civic and CR-V, with the third generation, the RDX uses its own platform. First generation (TB1/2; 2007) Originally previewed as the Acura RD-X concept car, the production RDX had its debut at the 2006 New York Auto Show and went on sale on August 11, 2006. A facelifted 2010 model went on sale in August 2009, which featured the addition Acura's "power plenum" grille and a front-wheel drive option. Engine The first-generation RDX is powered by a 2.3-litre straight-4 turbocharged gasoline engine, rated at at 6,000 rpm with a torque peak of at 4,500 rpm. At the time, this was uncommon among Honda vehicles. The K23A1 engine has all-aluminum construction, an i-VTEC head, and dual balance shafts. It was also one of the only four-cylinder powered luxury SUVs of its generation. Honda's variable flow turbocharger reduces turbo lag by using a valve to narrow the exhaust passage at low rpm, increasing the velocity of the exhaust flow and keeping the turbine spinning rapidly. At higher rpm, the valve opens to allow more exhaust flow for increased boost. The engine also features a top-mounted intercooler which receives air from the grille, channeled by ducting under the hood. The U.S. Environmental Protection Agency (EPA) estimated fuel mileage is city and highway miles per gallon. An updated EPA mileage estimate in February 2007 rated the RDX at city and highway. Drivetrain The first-generation RDX featured a version of Acura's Super Handling All-Wheel Drive (SH-AWD) and a five-speed automatic transmission with Acura's SportShift sequential shift capability, activated by paddles mounted on the steering wheel for 2007-2009 models (additionally FWD was offered in some trims for 2010-2012 models). The paddles can be used in Drive (D) to make a gear change with the transmission returning to automatic mode as soon as the vehicle resumes a steady-cruise state. The Sport (S) setting has higher shift points and quicker downshifts, and using a paddle in “Sport” immediately puts the transmission in fully-manual mode. The four-cylinder engines in the first-generation RDX all use a timing chain, whereas the V6 installed in subsequent years (2013-2018) all use timing belts. Interior The vehicle's interior includes standard leather seating, a moonroof, automatic climate