BODY DESIGN STRUCTURE
The 2012 Acura RL incorporates exterior bodywork that generates a crisp, yet muscular, luxury performance sedan. The RL combines its dynamic exterior and interior design with advanced body and chassis engineering. The result is distinctive and appealing styling, together with excellent maneuverability on the road. To ensure that the RL has exceptional dynamic capabilities and driving quality, it is outfitted with a lightweight and highly rigid body structure that makes extensive use of both high-tensile steel and aluminum components, and it features 4-wheel independent suspension.
Acura designers wanted to create a taut and athletic shape that conveyed the performance capabilities of the RL without sacrificing comfort and capability.
To create an exhilarating, athletic sedan, the designers targeted superior dynamic performance, superb maneuverability, distinctively appealing styling, and a high level of active safety. The result is a top-flight luxury performance sedan able to compete with the Audi A6, BMW 5 Series, Mercedes-Benz E Class and others.
Acura designers applied a “Keen Edge Dynamic” look to bring character and athleticism to the RL. To help craft the design image, styling cues include the following:
- Aerodynamic design with low drag and improved high-speed stability
- Acura’s signature front grille that is in design concert with the Keen Edge Dynamic design grille for all new Acura vehicles
- A front hood constructed of lightweight aluminum and designed for increased forward visibility and reduced aerodynamic drag
- A trunk lid that reduces rearend lift at high speed and provides added visual character
- Aggressively styled front and rear bumpers
- Lower rocker panel side moldings with inset chrome trim accents
- Flush-mount side glass for reduced wind noise
- Aggressively styled headlights that incorporate Active Front Lighting System (AFS)
- Aggressively styled rear taillights
- Reverse gear back-up lights integrated into the rear trunk lid for improved visibility
- Hexagonal-shaped, polished chrome dual exhaust tips
The specific aerodynamic properties of the RL complement the styling, safety, dynamic performance, stability, human factors and other considerations. To achieve this high-performance exterior, the RL designers created a strong wedge shape that begins its “momentum” with the hood, continues it with a forward-mounted acoustic glass windshield, and finishes with a short rear overhang. The aerodynamic cabin has flush side glass for reduced drag and less wind.
The packaging goal for the RL was to create a taught body with short overhangs while simultaneously providing wide interior dimensions for enhanced comfort and convenience. Controlling the weight of the RL is important for maximum acceleration, road holding and braking performance — thus, lightweight materials and weight-saving design are key.
Producing a lightweight and rigid unit body was essential to making the RL a premium luxury performance sedan. Lightweight construction techniques improve every aspect of the RL’s dynamic performance and fuel economy, and a rigid structure improves ride and handling quality.
Specific RL strategies employed to reduce body mass include:
- Aluminum hood, front fenders, trunk lid and trunk lid frame
- Aluminum front and rear subframes, suspension arms, front knuckles and bumper beams
- Magnesium intake manifold, cylinder head covers and seat frames
- Carbon fiber reinforced composite driveshafts
The Acura RL was also designed with the goal of creating an automobile body that provides world-class safety. It was engineered to comply with the latest FMVSS208 occupant crash protection standard and FMVSS301 fuel system integrity standard.
One of the most difficult test modes to achieve is the side collision that models the impact of a RL being struck from the side by an SUV or a pickup truck. To meet these benchmarks, engineers increased the side section of the frame to comply with new collision regulations (see Safety section for more information). Engineers also chose different material specifications to provide the desired level of stiffness and strength for critical areas, without adding unnecessary weight.
- The use of aluminum for the front and rear bumper beams, hood, trunk lid and front fenders saves 40 pounds compared to if constructed from steel
- Extremely strong Grade 80 high-tension steel is used for the side sills, under-floor spars and in the impact-absorbing crumple zones at the front of the side frames
- High tension Grade 45 steel used on the front shock mounts, front passenger-compartment bulkhead, areas of the front subframe mounts and rear structure
- Grade 60 steel is used for 31-percent of the body construction
The overall result is a high level of bending and twisting rigidity for the unit body combined with enhanced crashworthiness– all with no additional weight penalty.
The RL’s lightweight aluminum front fenders, trunk and trunk frame are formed with an innovative build process called blow forming to achieve complex shapes– all with a high level of quality, low cost and lightweight construction. First, the raw aluminum panels are placed in a heated mold and warmed to 500-degrees Celsius. Next, the aluminum panels are forced into the mold with a high-pressure gas. The result is perfectly formed complex shapes that are not possible with traditional stamping methods.
For rigidity, the trunk lid is composed of an inner structural panel and an outer body panel. This 2-piece aluminum structure is crimped together with self-piercing rivets that make the lid highly durable.
Safety in side collisions, along with the pursuit of a quality door-closing sound, drove Acura engineers to design unique door structures. Special beams were applied for side-impact safety in both the front and rear doors.
There is no mistaking the quality sound that a well-engineered door makes as it is closes. By positioning door’s center of gravity (the height at which its weight is centered) at the same height as the latch, audible vibration and the resulting closing sound can be improved. For improved entry and exit, the rear doors open an impressive 80-degrees.
The aerodynamic trunk lid has been designed to reduce rear lift at high speeds. The aluminum trunk lid also reduces weight while providing improved styling with a European flair.
The trunk opening is reinforced to retain rigidity while providing a large, low opening for easy loading. Inside, the trunk opening is finished to hide the hinges and to cover the rain gutters.
To decrease wind noise levels and improve appearance, the RL incorporates hidden pivots and wiper arms for its speed-sensing, variable intermittent windshield wiper system. The wiper pivots are hidden underneath the trailing edge of the hood line to reduce noise levels, improve aerodynamics and enhance appearance.
The use of hidden windshield wiper pivots is a world’s first. The pivot design improves aerodynamic efficiency and reduces visual distraction when the wipers reverse direction. A cowl garnish below the windshield wipers reduces air turbulence, helping contribute to a significant reduction in wind noise.
Careful design consideration has been paid to external and underbody design to generate excellent aerodynamics with the RL. An efficient aerodynamic drag coefficient of 0.30 pays dividends in the form of lower wind noise, improved fuel economy, increased performance and enhanced stability on the highway. The RL employs underbody aerodynamic panels that include a front spoiler, front tire strakes, engine undercover, floor undercovers, rear suspension lower control arm covers, rear tire strakes, exhaust pipe aero plates and a rear floor cover. The reinforced front air dam reduces front end lift while the rear trunk lid spoiler reduces rear end lift. The RL’s underbody covers not only smooth airflow, but also help with rear differential cooling.
XENON HIGH-INTENSITY DISCHARGE (HID) HEADLIGHTS
Traditional headlight bulbs illuminate a tungsten filament inside a sealed bulb containing halogen gas. However, Xenon High-Intensity Discharge (HID) bulbs use an exceptionally high voltage that passes between two electrodes to create a plasma arc. This intense arc accounts for the HID brightness and daylight-like illumination.
Xenon is superior to tungsten-halogen bulbs in lumens– or lighting power. The RL’s Xenon HID bulbs provide 825 lumens along with a lighting pattern that is both longer and wider than that of traditional non-Xenon bulbs. In addition, the RL’s tungsten-halogen high beams provide a wide illumination spread. For the driver, these advances mean greater nighttime illumination for enhanced driving confidence.
Additionally, the Xenon HID low-beam headlight bulbs have a projected life span of 1,500 hours compared to 1,000 hours for a normal bulb.
ACTIVE FRONT LIGHTING SYSTEM
The RL uses aggressively styled front headlight assemblies with integrated brushed-style metallic surrounds and trim accents. Acura RLs equipped with the Technology Package feature an Active Front Lighting System (AFS) that uses Xenon High-Intensity Discharge (HID) headlights, 55-watt fog lights and daytime running lights (DRL).
In the Active Front Lighting System, the left low-beam unit can swivel left and the right low beam can swivel right to improve nighttime illumination while cornering, or to help illuminate around the corner of an intersection. This improved illumination allows the RL driver increased opportunity to see if a pedestrian, animal, or object is in the way. Each HID headlight can independently swivel laterally up to 20-degrees, with the total amount of movement determined by vehicle speed and steering input.
The Active Front Lighting System uses the following components:
- Steering angle sensor
- Vehicle speed sensor
- Control unit swivels the low beam headlight projector unit via a gearbox motor
- Reverse switch (cancels AFS when car is backing up)
- Control switch (turns off AFS at driver’s discretion)
- Instrument panel warning light (illuminates when AFS is turned off)
AFS swivels either the left or right headlight (not both simultaneously) when the following conditions are met:
- Steering angle is over 12-degrees
- Vehicle speed is 5 mph or higher (left-hand turns only)
- Right-hand headlight will swivel even if vehicle is stopped
- Swivel cancels when speed drops to 3 mph (left-hand turns only)
DAYTIME RUNNING LIGHTS
In Acura’s continual commitment for safety, the 2012 RL features Daytime Running Lights (DRL) to improve visibility while driving.
The 2012 RL features advanced Light Emitting Diode (LED) lighting systems. These include side mirror-integrated directional turn signals, each of which features bright LED lights to alert motorists who are alongside when the RL driver is planning to change lanes or make a turn.
Each rear taillight assembly has an array of 28 LEDs. The taillights use 14 LEDs, arranged as the perimeter of a circle, and the brake lights use an additional 14 LEDs. When the brakes are applied, all 28 LEDs light up, illuminating the entire area. The RL’s center high-mounted stop lamp (CHMSL) also uses LEDs. Besides providing a high-tech look, LED lights react quicker (they turn on/off more quickly) and produce crisper illumination than traditional bulbs, which translates to greater visibility. The projected service life of the RL’s LED lights is an impressive 2,000 hours.
5 MPH BUMPERS
To minimize repair costs in minor, low-speed collisions, the RL has “5-mph bumpers” front and rear that are designed to absorb low speed impacts without causing any structural damage to the body panels or chassis.
NOISE VIBRATION AND HARSHNESS (NVH)
The elimination of undesirable noise, vibration and harshness (NVH) for the RL was of primary concern to development engineers. Virtually everything that could be the source of such NVH traits was scientifically reviewed and modified during the planning and prototype phases.
Consequently, the RL receives significant amounts of sound-deadening insulation and unique body separators that use a stamping design with injected foam to help quell road noise from entering the RL’s interior cabin. As part of the mission to control weight, Acura uses lightweight materials wherever possible in the sound-absorbing package, including lightweight sound insulators instead of traditional heavier materials. In addition, special shock absorber and coil spring parameters help prevent road harshness from being transmitted to interior occupants. A dual exhaust system fit with six mufflers (of differing size) reduces exhaust noise while cruising. The RL uses an acoustic glass front windshield that incorporates a PVB film to quell wind and windshield wiper noise from entering the cabin.
A unique Active Sound Control system uses an array of processing technology and sensors to generate accurate sound cancellation throughout the entire engine rpm range (earlier designs only worked to cancel engine booming noise up to 2,000 rpm). In addition, the RL’s Active Sound Control system dramatically reduces high frequency and middle-frequency noise attenuation.
Key RL NVH advancements:
- Engine mounting system including a hydraulic lower transmission mount
- Variable volume exhaust mufflers
- Under-hood insulator
- Engine cover and undercover
- Acoustic roof lining
- Acoustic front and rear inner fender insulator with high-frequency damping materials
- Acoustic glass windshield
- Lightweight floor insulator
- Floor undercover
- Floating front and rear subframes with four mounting points
- Active Sound Control system for noise control
- Lightweight instrument panel damping materials
- Thinsulate® insulation in selected areas
- Acoustic design with side, front and lid linings
The RL’s power actuated side door windows are made of tempered glass that is 5 mm thick to help reduce cabin noise. Each window features an auto-open and auto-close function, an auto-reverse safety feature, as well as key-off operation. The side glass is a special UV-coated, heat-rejection design “green glass” that helps protect occupants from harmful UV rays and excessive interior heat build-up. In an effort to further reduce cabin heat–as well as to provide added rear seat privacy–the RL features a power operated rear sunshade along with manually operated rear door glass sun shades.
Flush Mount Glass
The Acura RL is the first car in the world to have flush side glass where it meets the B-pillars. Normally, a gap of about 5 mm exists between side glass and the B-pillar. On the RL, the window guide is on the glass instead of the window frame, which allows the gap to be virtually eliminated. This design results in one continuous uninterrupted plane running along the front side window, across the B-pillar and all the way to the trailing edge of the rear side window. The benefit is improved aerodynamics, a reduction in wind noise and a cleaner appearance.
EXTERIOR SIDE MIRRORS
To reduce wind rush and turbulence, exterior side mirror housings need to be small and aerodynamic without unnecessarily reducing the mirror area. On the RL, the power mirror element is sized to fit inside a compact housing to reduce these unwanted characteristics.
The airflow between the mirror housing and the side window glass is crucial for reducing turbulence and noise. Engineers designed this gap as an expanding V-shape, with the gap narrower at the front and wider at the rear. This design helps the airflow decelerate as it flows across the side glass, instead of accelerating as it would if the V-angle were to decrease. The result is smoother airflow and less mid- and high-frequency noise.
The mirrors also feature integrated directional turn signals to improve visibility and to alert other vehicles of the RL’s intended actions. In addition, the side mirrors are heated to deter ice or fog build-up in cold weather conditions and the mirrors feature a special coating that reduces nighttime glare. When the RL driver puts the transmission in Reverse, the passenger-side mirror tilts-down to reveal curbs and ground level obstacles to avoid. To generate added convenience, the mirrors feature driver recognition that automatically adjusts their position to preset parameters of a specific driver profile.
The exterior paint on the Acura RL is applied using an environmentally conscious water-based process. The painting procedure begins with an electrodeposition (ED) primer, which is electrically charged in the paint bath to help the primer better adhere to the metal bodywork. The ED primer is cured at high temperature to improve corrosive durability.
Next applied is a primer-surfacer that is hand sanded to ensure a smooth surface for better appearance. After a waterborne color basecoat is applied, a pair of clearcoats provides depth while helping to protect the base coat from air pollution, acid rain and sun damage.
Six different exterior colors are available, including three metallic colors and three pearl colors. All six colors are selectively available with three different interior colors. The chart below shows the available exterior/interior color combinations.
2012 RL EXTERIOR ACCESSORIES
A line of dealer installed Genuine Acura Accessories was developed simultaneously with the RL to provide personalization for the Acura owner. Like all Genuine Acura Accessories, the RL accessories are covered by a 4-year/50,000-mile limited warranty if installed by the dealer at the time of original vehicle purchase.
- Rear deck lid spoiler
- Rear bumper appliqué
- Door edge protection film
- Door visor
- Moon roof visor
- Car cover
- Front end nosemask
- Color-matched splash guards
- Engine block heater
- Wheel locks
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