The Acura RDX(Chassis Code TB1) is Acura’s first compact crossover SUV. 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. The RDX takes over from the MDX as Acura's entry-level crossover SUV, as the MDX continues to grow in size and price. Although the dimensions of the vehicle are similar to that of the Honda CR-V, the RDX uses a unique platform developed to handle the vehicle's advanced all-wheel drive system. A facelifted 2010 model went on sale in August 2009, adopting Acura's power plenum grille seen on its sedan models. Front-wheel drive was also added. The RDX is powered by one of Honda's very few turbocharged gasoline engines. The 2.3-litre straight-4 K23A1 engine has all-aluminum construction, an i-VTEC head, and dual balance shafts. It is also one of the first and only four-cylinder powered luxury SUVs. 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 Acura RDX engine is rated at 240 bhp (179.0 kW; 243.3 PS) at 6000 rpm with a torque peak of 260 ft·lbf (350 N·m) at 4500 rpm. The U.S. Environmental Protection Agency (EPA) estimated fuel mileage is 19 mpg-US (12 L/100 km; 23 mpg-imp) city and 23 mpg-US (10 L/100 km; 28 mpg-imp) highway miles per gallon. Driving style and the terrain plays an important part in this Vehicle's fuel economy. Uphill driving, frequent lane changes and sudden accelerations can increase turbo usage to increase torque output to the SH-AWD system and thus cause much higher fuel consumption. New more recent EPA mileage estimates as of February 2007 are 17 mpg-US (14 L/100 km; 20 mpg-imp) city and 22 mpg-US (11 L/100 km; 26 mpg-imp) highway. The recommended fuel is premium 91 octane unleaded.
The Acura RDX comes standard with a five-speed automatic transmission with Acura's SportShift sequential manual shift capability, activated by paddles mounted on the steering wheel. 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 full manual mode. The RDX also has a version of Acura's Super Handling All-Wheel Drive (SH-AWD), first seen on the flagship RL sedan. The system can vary the front/rear torque distribution from 90/10 to 30/70, depending on whether the vehicle is accelerating, cruising, hill climbing, taking a curve, or encountering poor road conditions. When taking a curve, a pair of magnetic flux clutches in the rear differential can transfer as much as 100% of the available rear torque to the outside wheel. That torque transfer, combined with a 1.7% rear over-rotation of the rear wheel helps rotate the RDX through a turn. The RDX seats five and comes standard with leather seating, a moonroof, automatic climate control, and all the expected power features. The RDX 7-speaker audio system features an in-dash 6-CD changer, which is capable of playing standard Audio CDs, and Data-CDs burned with either MP3 or WMA files, it also plays DVD-A type CDs. The RDX's sound system also includes XM Satellite Radio with a complimentary 3-month subscription. Much of the interior technology introduced in the RL sedan is found in the optional "Technology Package". This package includes the latest version of Acura's navigation system, complete with a rear view camera, XM Nav-Traffic real-time traffic monitoring, and Zagat restaurant reviews. The package also features a 10-speaker Acura/ELS audio system with DTS and Dolby Pro Logic II surround sound. The audio system plays DVD-Audio discs as well. Both stereos come with a 1/8" auxiliary input jack, which may be used to plug in external sources such as iPods. For 2007, Acura also offered an iPod adapter for the RDX, which was wired into the glove box, and allowed the iPod to be controlled through the RDX's sound system interface. Due to hardware incompatibilities the Honda/Acura iPod musiclink has been discontinued as of model year 2008. Current (2011) models come standard with a USB connection that interfaces with Apple inc.® iPod® players and other USB mass storage devices, such as flash drives that contain MP3, WMA6 or AAC music files while being stored in the center console.
Almost all of the ELS sound system's operations can be activated by voice command, as can most of the operations for the navigation and climate control systems. In addition, the vehicle will interact with most Bluetooth-equipped cell phones. The driver can initiate or receive calls through verbal command. During the call, the sound system will mute and channel the call through the speakers while caller and signal information is displayed on the instrument cluster. The tailgate opens over six-feet high and 60/40 rear seatbacks fold down for a flat cargo area. A hard cargo cover can fit flush on the floor when not needed and is reversible to carry wet or dirty cargo. The cabin includes several storage areas including a lockable center console that can hold a standard size laptop computer. The cargo hold is small size compared to most rivals and does not have the adjustable cargo tracks or a rear parcel shelf. The Acura RDX is the second Acura vehicle to feature the Advanced Compatibility Engineering (ACE) body structure which is designed to absorb energy from a collision. The RDX comes standard with six airbags, including dual front airbags, front side airbags and dual side curtain airbags. The front airbags use a dual-threshold, dual-stage technology that can adjust the timing and speed of each airbag deployment depending on the degree of impact and the driver's or front passenger's seat belt usage. If sensors deem the front passenger too small (less than 65 lb (29 kg)), the front airbag is designed not to deploy. The front passenger's side airbag is also designed to shut off if a child or small statured-adult is leaning into the airbag's deployment path. In the event of a sufficient side impact or roll-over, the side curtain airbag deploys from above the door frames of the affected side, with coverage for both the front and rear occupants on that side, and stays inflated longer than if there were a collision. Front seats have active head restraints and their seat belts are equipped with pre-tensioners and force-limiters. As of November 2006 the RDX was crash tested by the NHTSA, resulting in a perfect "5 Star" rating for driver and passenger frontal crashes, and front and rear side impacts, along with "4 Stars" for rollover.