Acura Automobiles: 2015 Acura TLX: Body

The TLX body is designed to support the twin goals expressed in the vehicle’s “Red Carpet Athlete” development theme – significantly enhanced luxury appeal, in terms of cabin quietness, ride comfort and styling refinement, and exhilarating and athletic sports-sedan performance – while also achieving class-leading fuel economy and crash safety ratings.

To achieve these sometimes-competing goals, Acura engineers created an all-new body design utilizing advanced materials, including ultra-high-strength steels, aluminum and magnesium, for rigidity, collision performance and weight savings. Special attention was paid to local body rigidity in areas where the body meets up with the suspension, engine and subframes, and to improvements in body sealing and noise insulation.

Vehicle aerodynamics also played a critical role in achieving class-leading fuel economy ratings. The TLX aerodynamics are improved by 15 percent (CdA) over the previous TL  and based on internal testing, is the best (lowest) in its competitive class. At the same time, the body also is designed to provide a high level of occupant crash protection incorporating Acura’s latest thinking in advanced body design, including the next-generation of Acura’s Advanced Compatibility Engineering (ACE) front body structure and one-piece hot-stamped-steel door ring, first applied to the all-new 2014 Acura MDX (see SAFETY section for more detail).

Key TLX body features found in this section include:

  • Rigid, lightweight body
  • Hemmed rear wheel arch
  • Ultra-high strength  steel
  • Aluminum components
  • Magnesium steering hanger beam
  • Advanced Compatibility Engineering (ACE) body structure
  • Jewel Eye™ LED Headlights
  • LED fog-, tail-, puddle-, license- and side-mirror lights
  • Auto-dimming side mirrors
  • Acoustic glass windshield
  • Acoustic foam applied to critical body sections
  • Electric trunk lid and fuel lid release
  • Cap-less refueling
  • Expanded View Driver’s Mirror
  • Exclusive Acura exterior colors (Black-Bronze and Acura Silver Metallic)

Dynamic and Athletic Proportions
With its low and wide stance, the new 2015 TLX possesses a lithe exterior form, taut body surfaces and “just right” proportions for a sports sedan. This sporting character is further defined by shortened front and rear overhangs, dynamically sculpted fender arches, and purposeful character lines. Even the sculpted hood, with its sharply creased bilateral ridgelines, hints at the performance capabilities of the advanced new Acura powertrains it conceals. Meanwhile, the open and airy greenhouse provides commanding sight lines, with slim A-pillars providing improved visibility.

“Just Right” Dimensions
The 2015 TLX’s “just right” body dimensions result from a careful balance of aerodynamic efficiency, interior roominess, dynamic performance, quietness and refinement, and design. Compared to the previous TL, the new TLX has the same 109.3-inch wheelbase, but is 3.8 inches shorter in overall length. This positions it between the smaller ILX entry-luxury sedan and flagship RLX sedan.  Despite its more compact exterior footprint, the TLX offers a spacious interior that approaches the previous TL.

In comparison to its competitors, the TLX is longer than the Audi A4, BMW 3 Series, Lexus IS and Mercedes-Benz C-Class. It is also significantly wider than all of its direct competitors, including the Lexus ES and GS, and Mercedes-Benz E-Class.

Rigid Lightweight Body
Light weight and rigidity are the twin foundations for TLX comfort, handling and safety performance. Light weight is achieved by a combination of advanced engineering and the use of high-strength steel, magnesium and aluminum unit-body components. TLX body rigidity is enhanced by precise engineering, particularly in optimizing key component fitting points (up to 25 percent stiffer) for superior bending stiffness, and the unit-body structure’s torsional rigidity is up 21-percent vs. the previous TL.

Aerodynamic Efficiency
In order to improve fuel efficiency and lower emissions, Acura designers merged the TLX’s dynamic styling with a high level of aerodynamic efficiency, with a reduction in frontal area and lower running resistance (the amount of energy that is lost as the car moves along the road and through the air) as key goals.

Most of the running-resistance improvements are achieved via refinements to the TLX’s body design, with even the smallest details calculated and confirmed by the use of sophisticated computational fluid dynamics (CFD), as well as scale wind tunnel and high-precision coast-down testing.

The new TLX is 0.4-inch lower and 1.0-inch narrower, with a slightly longer roofline, than the previous TL model. The result is 1.5-percent less frontal area than the previous TL, along with a 15-percent improvement in aerodynamics (CdA). Slightly narrower 225mm wide tires also replace the 245mm wide tires on the TL, further improving running efficiency. The end result is 16-percent reduction in running resistance compared to the previous TL. Internal testing shows the TLX to be the most aerodynamically efficient car in its class.

Hemmed Rear Wheel Arch
The rear wheel arches on the TLX use a special roll-hemming process that results in a cleaner edge and smoother appearance than on the previous TL model. In simple terms, the wheel-arch “hems” are the curved sheet-metal edges that surround the rear tires. In the new TLX, a special hemming process is used instead of spot welds to join the inner and outer fender sheet-metal on the inside of the fender opening. The result is a reduced tire-to-fender gap which improves aerodynamics, elimination of visible spot-welds and a cleaner appearance.

High Strength Steel
To achieve the high rigidity that promotes a smooth and quiet ride, crisp steering and handling, safety performance and long-term durability, the TLX utilizes six different grades of high-strength steel (HSS) in 52% of its body structure by weight. This high-grade, high-tensile strength steel adds the required rigidity for these positive traits without adding excessive weight, which in turn enhances fuel efficiency and lowers emissions. Altogether, 59-percent of the TLX body is created from a combination of high-strength steel, aluminum and magnesium.

High strength steel uses include:

  • UISBOR – USIBOR is a boron-alloyed steel with an aluminum-silicon coating that protects against oxidation during the heating, forming and hardening process. This high-strength hot-stamp steel is used for the TLX’s door opening rings, for 5% of the unit body. (See Safety section for more information.)
  • 980 grade HSS – Used in certain key structural points such as the front edges of the door sills, and in the A-pillars and B-pillars, for 2% of the unit body.
  • 780 grade HSS – Used for most structural load paths for ACE™, including the side sills and forward spars of unit body, for 2% of the unit body.
  • 590 grade HSS – Used for the front frame spars, floor and roof supports, for 35% of the unit body.
  • 440 grade HSS – Used in the front bulkhead, and in front and rear energy-absorbing structures, for 5% of the unit body.
  • 340 grade HSS – Sheet steel is used in the roof, for 3% of the unit body.

Aluminum Components
Aluminum stampings are used in certain key locations to reduce the TLX’s curb weight, which provides benefits in handling, fuel efficiency and emissions reductions. Altogether, the aluminum components comprise 6-percent of the TLX’s body weight, a savings of 27.8 pounds compared to comparable steel components.

Among the aluminum body components are:

  • Hood
  • Front bumper beam
  • Rear bumper beam
  • Front subframe (hybrid aluminum/steel)

Magnesium Steering Hanger Beam
Located behind the instrument panel, a 3-piece magnesium steering-hanger beam replaces the 26-piece aluminum and steel unit in the previous TL model. Its purpose is as a structural attachment point for the steering column, pedals and instrument panel, as well as a structural element that helps the passenger cabin retain its shape in certain collisions. This single robust magnesium component makes up 2-percent of the TLX’s body weight.

The steering-hanger beam offers several advantages compared to the previous unit:

  • Simpler construction — Created from just three parts instead of the previous 26 different extrusions and stampings, the new magnesium steering hanger brace offers better construction precision.
  • Lighter weight — The magnesium steering hanger beam saves 2.7 pounds compared to a comparable aluminum and steel, contributing to the TLX’s superior ride and handling, fuel efficiency and low emissions.
  • Better fit and finish — The exacting tolerances of the magnesium steering hanger brace in turn allow the instrument panel to fit better, exhibiting higher overall interior quality.

LED Lighting
The most comprehensive use of LED lighting on any Acura vehicle is a signature design element of the new TLX. From the dramatic Jewel Eye™ headlights to the convenient new puddle lights and back to the new taillights, the LED lighting provides crisp, bright, energy-efficient and long-lasting illumination that directly improves the driving and ownership experience. A summary of exterior lighting includes:

Forward Lighting

  • New LED headlights with incandescent-bulb turn signals
  • New LED parking and side marker lights
  • New LED under-mirror puddle lights (Advance grades)
  • LED front fog lights (Advance grades)

Rear Lighting

  • New LED tail and trunk-lid lights with incandescent-bulb turn signals and backup lights
  • New LED Center High Mount Stop Lights (CHMSL) with integrated cover
  • LED license-plate lights

Jewel Eye™ LED Headlights
Acura’s signature Jewel Eye™ LED headlights give the TLX with an advanced and appearance while producing superior down-the-road illumination. The headlights utilize an array of high-intensity LED lamps to deliver outstanding light distribution, distant irradiation performance and light characteristics with a wavelength close to the human eye’s luminosity curve. With five “Jewel Eye” lights per headlight, the LED lights provide improved down the road visibility compared to HID and halogen headlights.

On each side of the TLX, the low beams consist of three LED lights, while the innermost LED lights are utilized for high beams. The daytime running light (DRL) function utilizes all five lenses illuminated by LED’s that are clearly and dramatically visible even in bright sunlight. Altogether, they create a dramatic and distinctive appearance with superior lighting capability.

Light distribution
Both the low and separate high beam LED headlights offer outstanding performance in all nighttime driving conditions, including highway, winding roads, intersections, and in inclement weather conditions. The result is that the driver can see further with uniformity, making high-speed nighttime driving easier and less fatiguing.

A summary of LED benefits include:

  • Outstanding light distribution that surpasses competitors
  • Excellent distant illumination performance
  • Clear illumination of the road surface and white lines
  • High visibility of the entire visible color spectrum (white, red, green, blue and yellow) compared to HID and halogen headlights
  • Response time when switching between low and high beam is shortened
  • Light congruity is improved between low and high beams

Power savings
Using just 65 watts total, the TLX’s LED headlights use 41-percent less power than traditional halogen headlights, contributing to the TLX’s overall operating efficiency.

Long lasting
Besides producing better light characteristics with lower energy usage, the TLX’s LED headlights are longer lasting. With an estimated life expectancy of 10,000 hours, the LED headlights are projected to last five times longer than HID headlights and 10 times longer than traditional halogen headlight bulbs — contributing to less frequent replacement and potential associated cost savings. Further, their compact packaging allow for an improved aerodynamic frontal design.

LED Fog Lights
Included in the Advance Package, LED fog lights are positioned at the lower corners of the TLX’s front fascia for maximum effectiveness and a bold appearance.

LED Taillights
LED taillights are part of the TLX’s comprehensive exterior lighting array. Highly stylized to compliment the TLX body design, they are also brighter than traditional incandescent-bulb taillights, with a longer projected lifespan. Use of LEDs allows the addition of a “light pipe” styling element extending across the top of the lenses, contributing to the TLX’s unique blend of design and engineering.

LED Puddle Lights
Included in the standard Smart Entry system, LED puddle lights positioned on the undersides of both side mirror housings enhance convenience when entering or leaving the vehicle. The LEDs automatically illuminate when the TLX detects the key fob approaching, in concert with the automatic interior illumination. The puddle lights also illuminate when the driver puts the TLX in Park and leaves the vehicle, fading off after about two seconds after locking the doors, or 30 seconds if the doors are not locked.

LED Side Mirror Lights
Keying off of the Jewel Eye™ LED headlights, each TLX mirror has LED lights fused into the mirror housing. The LEDs come to life when the turn indictors are activated, providing extra visibility and a high tech appearance.

Auto-Dimming Side Mirrors
Included in the Advance Package, auto-dimming side mirrors use the same activation sensor as the TLX’s auto-dimming inside rearview mirror. The auto-dimming function of all three mirrors helps reduce glare during nighttime driving, especially from the headlights of following vehicles. Mirror glass area is 24-percent greater than on the previous TL model for improved rear visibility.

Expanded View Driver’s Mirror
An Expanded View Driver’s Mirror performs like two mirrors in one. The larger, inset portion of the mirror is relatively flat and works like a conventional sideview mirror to show objects to the side of the vehicle. The outer portion of the mirror is optically convex and functions as a wide-angle mirror to expand the driver’s view to the side by approximately 39 percent, helping to reduce the blind-zone area.

Acoustic Glass
To reduce noise in the cabin The TLX utilizes a 4.5-mm thick, 3-layer acoustic windshield that consists of two layers of safety glass, separated by a thin acoustic resin center. The windshield reduces wind noise on in the higher frequency ranges, contributing to a luxurious feeling of isolation in the cabin. Also helping to mitigate wind, road and traffic noise in the cabin is 5.0-mm thick front door glass.

Auto Up-Down Side Windows
The 2015 TLX has power front and rear side windows with an auto-open and auto-close feature with anti-pinch.

Advanced Windshield Wiper System
The sleek, flat design of the wiper blades adds to the TLX’s visual appeal. The flat blade design improves aerodynamic performance and reduces wind noise.

Headlights On With Wipers
Laws in some states require drivers to turn on the headlights when the wipers are operating in the rain. The new TLX helps its driver comply with these laws by automatically illuminating the headlights when the wipers are activated for five cycles or more (with headlight switch in AUTO). The headlights will remain illuminated for as long as the rain continues and the wipers are being operated. When the rain stops, the wiper activation also ceases, with the headlights remaining lit until the wipers stop. Operation is shown via an indicator on the instrument panel.

Rain Sensing Wipers
TLX models equipped with Technology Package and Advance Package include rain-sensing wipers that automatically activate if water is detected on the windshield.

Noise Mitigation
The TLX was designed to deliver vault-like quietness in all driving conditions, with major improvements achieved through enhancements in body stiffness, body and door sealing, and widespread sound insulation.

Acoustic Spray Foam
Applied to the unit body in 10 crucial locations around the door openings, acoustic spray foam helps create a solid foundation for a quieter cabin. The application process is automated and computer controlled, with the foam curing in 7 to 11 seconds after application for a highly precise and effective process.

Additional Materials and Sealing
Additional sound-absorptive materials are used throughout the unit body and interior, each dedicated to blocking a particular noise type and frequency. The materials include Thinsulate insulation, body sealers, noise-absorbing carpeting, and a high-density and dual density melt sheets. Liquid Applied Sound Deadening (LASD) is used in the trunk.  Key areas of attention include the TLX’s dashboard lower and floor area. Total body leakage is reduced 50 percent vs. the outgoing TL. The end result is reduced road noise and drumming on both concrete and asphalt surfaces, along with lower engine noise, for a more relaxing and pleasant driving experience.

Wind Noise
Significant improvements in both high-frequency and mid-frequency noise heard in the cabin were achieved by lowering the windshield-wiper height and optimizing the shape of the side mirrors. Special sealing methods in the B-pillars and C-pillars, and between the door gaps, further reduce audible wind noise.

Improved Door Sealing
The new TLX adopts the previous TL’s 360-degree double seals that completely surround each passenger door. In addition, the TLX uses a third set of gap seals, positioned at the front, center, rear and bottom edges of each door, that help eliminate potential noise source caused by turbulent airflow in the cavities around the door hinges and latches. The doors’ internal steel stampings receive further sound insulation in the form of large acoustic hole seals, internal foam sound barriers, and specially targeted B-pillar plugs.

Electric Trunk Lid Release
There are four ways to open the trunk: 1) by pressing the trunk opener switch located on the driver side instrument panel; 2) with the key fob; 3) with the trunk opener switch located in the middle of the trunk, underneath the trunk lid overhang; and 4) if the electric trunk release is inoperative, the trunk may be unlocked and opened by using the key stored in the key fob. The trunk’s emergency key cylinder is located beneath a cover near the head restraint on the driver’s side rear seatback.

Trunk Storage
The base TLX and TLX with Technology package offer a 13.2 cu. ft. of cargo volume, while the TLX with Advance Package has a larger 14.3 cu. ft. of cargo volume. There is no difference in storage capacity for the TLX two-wheel-drive models and TLX SH-AWD.

Compared to the previous TL, the trunk features an easier load-in height, a wider opening, and a flat, wide trunk floor that makes loading and unloading cargo easier. In specific, the interior dimensions are 14-percent wider, 12-percent deeper, with a 15-percent lower load-in height than the TL dimensions. The new flat floor extends from the rear bumper area, forward to the rear seatback for improved usability. The trunk hinges are fully hidden for a better visual appearance and to eliminate the possibility of catching on stored items. New 60/40 split-folding rear seatbacks allow storage of large or bulky items such as bicycles, skis or boards, or flat-screen televisions. (See Interior section for more information.)

Cargo Bin System
All TLX models include a versatile trunk underfloor storage system that provides convenient storage for such items as groceries, emergency tools and other small items. The flip-up floor reveals a pair of storage bins (or a larger single bin with the Advance Package). These bins are ideal for everyday items such as groceries, shoes, etc. Flipping the floor panel again reveals an additional storage area designed for emergency tools, jumper cables, etc. A molded carrier holding the TLX’s towing eyebolt and tire-inflator kit is also located in this area. Finally, the Advance Package includes a reversible floor panel. Carpeted on one side, it features a plastic surface on the backside to be used when wet or messy items — for instance, wetsuits, beach towels or a car cover — need to be carried in the trunk.

Exterior Colors
The 2015 TLX is available in seven exterior colors, including two metallic and five pearl colors. All colors have a strong character, offering expressive contrasts that compliment the TLX’s body-panel curves and angles, while also exhibiting a smart luxury appearance. The acid-resistant epoxy clear-coat paint is superior to typical clear-coat paints for increased resistance to urban pollutants.

Acura TLX Exterior Colors

  • Acura Silver Metallic (New)
  • Basque Red Pearl
  • Bellanova White Pearl
  • Bronze-Black Pearl (New)
  • Crystal Black Pearl
  • Graphite Luster Metallic
  • Obsidian Blue Pearl