2009 mid-model change (KB2)

For the 2009 model year, the RL received an extensive mid-model change (MMC), and made its introduction at the Chicago Auto Show on February 6, 2008, billed as "the most extensive Acura MMC ever". The new sedan was designated KB2 in the VIN codes, differentiating it from the 2005–2008 KB1 chassis VIN code. The revised sedan was released on July 1, 2008 to dealerships. The engine is upgraded to 3.7L with 300 hp (220 kW). While on paper, the engine may seem to be the same unit as shared with the Acura MDX, it is actually a variant that introduces, for the first time ever on an SOHC Honda V6, an implementation of the Honda VTEC variable valve train technology on the exhaust side for improved horsepower and torque. Heretofore, all previous SOHC Honda V6 engines with VTEC used the technology on the intake side only.[17] Engine emissions were reduced to meet the stricter U.S. Environmental Protection Agency (EPA) TIER 2 – BIN 5 and California Air Resources Board ULEV-2 standards. Implementation of the SH-AWD was adjusted for earlier intervention and a greater rear-wheel bias for better handling dynamics.
The MMC RL suspension was upgraded with higher-rate coil springs, larger diameter anti-sway bars and stiffer bushings all around.[18] The MMC RL was equipped with a new larger front anti-sway bar of hollow construction, 30 mm diameter overall with a 6.5 mm wall thickness, and a larger rear solid anti-sway bar, 19 mm in diameter.[19] The pre-MMC models sported a solid 29 mm front and 17 mm rear sway bar.[20]
Standard 18- x 8-inch seven-spoke alloy wheels with 245/45-18 tires replaced the previous years' 17- x 8-inch five-spoke offerings for not only the Base and Tech package models, but also for the highest trim level, the ACC/CMBS equipped model. Previous years' ACC/CMBS equipped models were equipped with [Michelin PAX System] run-flat tires on 18-inch equivalent (460 mm diameter) five-spoke wheels.
Inside, the front seats were revised for greater comfort and to allow a slight increase in rear leg room. The passenger front seat received the same full 10-way power control as the driver's seat. Both front seats featured active head restraint systems, and the existing seat-heating feature was supplemented by six levels of cooling ventilation. Controls for heating and air conditioning were simplified, and additional individual vent controls were added for the driver and passenger. The shift gear no longer had a gated sequence, but moved straight fore and aft like the ones in the Acura TSX and Acura TL. Simulated woodgrain trim was addded to the steering wheel and the top of the shifter, to emphasize the RL's upscale aspirations compared to its less costly TL and TSX siblings.
Additional insulation, improved acoustic isolation windshield design, and a new implementation of the Active Noise Cancellation system (ANC) combined to make the 2009 RL's interior quieter in a variety of conditions. Whereas the former ANC was set to cancel out only low frequency boominess from the engine and exhaust, the MMC system, called Active Sound Control, was expanded in its range to cancel some higher frequency road and tire noise as well. Unlike its predecessor ANC, Active Sound Control was now linked to throttle position and engine RPM to provide a quieter cockpit during normal cruising, yet allowed more of the new 3.7L engine's "muscular sound" to be heard during higher-RPM, higher-speed excursions.
An additional microphone as well as some switchable directionality was added to the HFL (Hands Free Link) and Voice Activated Navigation and Convenience controls. When the system was in "accept commands" mode, the new microphone system provided more accurate system "understanding" of the driver's voice. Extraneous sounds, such as other voices in the cabin and wind noise, were better distinguished and filtered out by the dual microphone system. Directionality was removed when an HFL voice call was established, so that all passengers could still participate in a phone call as in the pre-MMC model. The new dual microphone system used real estate in the overhead console that was previously used in the 2005 and 2006 models for OnStar control electronics. The number of voice recognition commands was increased to over 700,[21] up from 560[22] previously.
The DVD-based navigation system improved on previous XM satellite-linked traffic flow reporting, adding continuously updated real-time weather reporting and the capability to reroute based on current traffic conditions. The DVD Audio-capable 10-speaker sound system remained, but integration with the audio system was improved with the addition of Bluetooth stereo and a USB port that allowed integration and operation of Apple iPod and other MP3 type devices. Also new was the ability to display iPod or other MP3 device (such as a USB flash memory device) folder and playlist information on the car's 8-inch central navigation display screen.[23]
New shifter and center console arrangements were added, including a Sport mode. The steering wheel paddle shifters were reprogrammed for faster response, and the paddle shifters could be operated in both Drive and Sport modes. In pre-MMC models, the gear selector had to be put in manual mode for the paddle shifters to operate.
In exterior length, the 2009 RL grew slightly by 2.2 inches (56 mm). The height grew by a scant 0.1 inches (2.5 mm), while the width, track and wheelbase remaind the same,.[19][20] The front end including the hood, and the rear including the trunkline, were revised, and the headlights and taillights redesigned. One of the most controversial features of the 2009 RL was its "Power Plenum" grille design, the first of three similar designs that was soon joined by the second-generation 2009 Acura TSX and the fourth-generation 2009 Acura TL.
Curb weights increased for 2009. The MMC Base weighed in at 4083 lbs, the Technology Package model 4085 lbs, and the ACC/CMBS with no PAX weighed 4110.[24] The equivalent 2006 pre-MMC Technology Package had weighed 4012 lbs, and the pre-MMC with ACC/CMBS/PAX weighed 4074 lbs.[25]
MSRP for the 2009 Acura RL increased by $500 over 2008 model for each of its three trim levels.[26] For 2009, the Michelin PAX Run Flat Tire system was no longer offered in combination with the CMBS/ACC package. ACC was now featured alongside CMBS as part of the package name, after a two-year hiatus. In reality, ACC was always included as a part of the CMBS. Colors were also added and deleted.