In early 2013, Acura introduced the 310-horsepower RLX luxury-performance sedan with a new 3.5-liter all-aluminum, direct-injected VTEC V-6 engine, a number of signature Acura technologies and Precision All-Wheel Steer™ (P-AWS™), creating a new value proposition with superior cabin space and outstanding driving performance in Acura’s flagship sedan. Acura is again raising the bar with the introduction of the RLX Sport Hybrid SH-AWD™, the most powerful and technologically advanced Acura sedan yet and the first to apply Acura’s groundbreaking new three-motor Sport Hybrid system with electric SH-AWD (Sport Hybrid SH-AWD).
With a direct-injected V-6 engine and an all-new 7-speed dual-clutch transmission (DCT) with built-in motor-generator powering the front wheels, and two rear electric motors powering the rear wheels, the 377-horsepower RLX combines V8-like performance and 4-cylinder-like fuel efficiency along with exhilarating “on the rails” handling performance, courtesy of its electrically-powered torque-vectoring all-wheel drive system.
The Acura RLX Sport Hybrid further elevates Acura’s commitment to create “the synergy between man and machine” -vehicles that truly respond to the will of the driver – and deliver new levels of technology-enhanced performance, comfort and convenience. Like the RLX with P-AWS™, the RLX Sport Hybrid delivers class-leading interior space and comfort and a host of signature Acura technologies, including Jewel Eye™ LED headlights, Lane Keeping Assist, Adaptive Cruise Control with Low-Speed Follow, and the next generation AcuraLink® connected car system. In addition, the RLX Sport Hybrid applies new Acura technologies including:
- Head-Up Display – this first-ever Acura head-up display projects key information at a glance on the lower portion of the windshield directly in front of the driver. Display modes include SH-AWD system operation, tachometer, turn-by-turn navigation, compass, ACC/LKAS along with vehicle speed.
- Electronic Gear Selector – the RLX also is the first Acura to feature Acura’s new fully electronic push-button gear selector, eliminating the conventional shift-lever and allowing the driver to select drive mode (Drive, Neutral, Park) at the push of a button. In addition, the system will automatically engage the Electronic Parking Brake when the driver selects park and unbuckles his/her seatbelt.
- Reactive Force Pedal – in place if a conventional spring mechanism providing force against the driver’s push on the gas pedal, the RLX Sport Hybrid utilizes an electric mechanism that dynamically varies pedal force to assist the driver in applying the optimum amount of engine power in any driving condition. For example, when climbing a snowy hill, the Reactive Force Pedal will increase pedal force to discourage the driver from applying too much engine torque that may lead to unwanted tire slip.
Using smart packaging, advanced aerodynamic design and lightweight body construction, along with fuel-saving hybrid powertrain technology, the RLX Sport Hybrid has the most spacious five-passenger seating in its class along with a top-class EPA fuel-economy rating of 28/32/30 mpg (city/highway/combined).
With a longer wheelbase and wider greenhouse than competing mid-luxury sedans, the new RLX Sport Hybrid SH-AWD delivers full-size interior space in a nimbler, mid-size luxury sedan package. The RLX boasts the longest rear-seat legroom (38.8 inches), and best front (59.6 inches) and rear (57.0 inches) shoulder room in the mid-luxury class. The RLX advanced body design makes extensive use of high-strength steel and aluminum, further aiding its outstanding fuel efficiency, straight-line performance, and superior handling agility.
The new RLX Sport Hybrid SH-AWD offers an incredible array of advanced safety, driver-assistive and information and media technologies, including the standard next-generation AcuraLink™ connected car system and Multi-Angle Rearview Camera; along with available Lane Keeping Assist System (LKAS), Adaptive Cruise Control with Low-Speed Follow and Blind Spot Information (BSI) system. Safety systems available on the RLX Sport Hybrid include technologies such as Collision Mitigation Brake System (CMBS), Forward Collision Warning (FCW) and Lane Departure Warning (LDW).
Utilizing Acura’s next-generation Advanced Compatibility Engineering™ (ACE™) body structure, along with seven airbags (including a driver’s knee airbag), the RLX Sport Hybrid SH-AWD is anticipated to earn top-level safety ratings, including a 5-star NCAP Overall Vehicle Score and an IIHS “TOP SAFETY PICK+” rating, including a GOOD rating in the IIHS small overlap front crash test.
The RLX Sport Hybrid also offers intuitive technology that reduces stress and simplifies the driving and ownership experience – with features such as Electronic Parking Brake with Automatic Brake Hold, a capless refueling system, Smart Entry/Smart Start keyless access system, easy-to-use and customize dual touch screens, “tensionless” e-pretension front seatbelts, and available rain-sensing windshield wipers, among others.
THE SYNERGY BETWEEN MAN AND MACHINE
As the foundation of Acura’s product direction, the Synergy Between Man and Machine is the intelligent pairing of useful technologies and luxury features with the idea of creating vehicles that truly respond to the will of the driver. The focus is not on one specific technology, but on the driving experience Acura vehicles provide to the customer. From its sophisticated exterior and interior design, to its balance of performance, low emission and the top-class fuel economy ratings, and advanced and intuitive technology, the RLX Sport Hybrid is designed to exceed the expectations of Acura clients.
The Acura RLX Sport Hybrid SH-AWD enters the mid-luxury segment competing against hybrid and/or all-wheel-drive versions of Audi A6, BMW 5-Series, Infiniti Q50, Lexus GS, and Mercedes-Benz E-Class. The RLX is equipped to meet these established competitors, thanks to improvements in virtually every area of its design, performance, technology, luxury and safety features.
RLX SPORT HYBRID DESIGN FEATURES
The RLX Sport Hybrid features numerous styling enhancements, inside and out, that distinguish it from the two-wheel drive RLX with P-AWS™. Its bold and elegant face is highlighted by a dark chrome-plated grille and redesigned lower bumper fascia with integrated LED fog lights and turn signal indicators. In profile, the RLX Sport Hybrid features model-exclusive 19-inch, 10-spoke alloy wheels and “Hybrid” badging on the left front fender. SH-AWD badging replaces the P-AWS badge on the right rear portion of the trunk lid. Inside the cabin there is a new light-gray instrument panel upper (replacing black on the RLX with P-AWS) and exclusive simulated wood accents on upper portion of glove box and center console.
RLX SPORT HYBRID MODEL RANGE
There are two grades of RLX Sport Hybrid – the feature-packed RLX Sport Hybrid with Technology package, and the line-topping RLX Sport Hybrid with Advance package. Major RLX standard features by grade are as follows:
RLX Sport Hybrid SH-AWD with Technology Package
- Super Handling-All-Wheel Drive™ (SH-AWD™)
- 3.5-liter Direct Injection SOHC i-VTEC® V-6 engine
- Variable Cylinder Management (VCM) cylinder deactivation system
- *Motor-Integtrated 7-speed Dual Clutch Transmission (DCT) with built-in 35-kilowatt (47 hp) electric motor
- Rear-mounted Twin Motor Unit with two 27-kilowatt (36 hp) motors
- Trunk-mounted Intelligent Power Unit with 72-cell, 1.3 kWh, 260-volt lithium-ion battery pack
- Double-wishbone, lower double-joint front suspension with a hydraulic compliance bushing and high-strength stabilizer bar
- Multi-link rear suspension
- Amplitude reactive dampers (front and rear)
- All-aluminum front subframe
- Active Control engine Mount (ACM)
- 19-inch, 10-spoke noise-reducing alloy wheels
- Michelin 245/40 R19 M+S all-season tires
- Electric parking brake
- Jewel Eye™ LED headlights
- Model-exclusive LED fog lights
- Model exclusive smoked chrome front grille, hybrid and SH-AWD badging
- Next-generation Advanced Compatibility Engineering™ (ACE™) body structure
- Hybrid aluminum-and-steel door construction
- Aluminum hood
- Capless refueling system
- Rain-sensing wipers
- Acoustic windshield and side glass
- Power retractable side mirrors
- Smart Entry (all four doors and trunk) with Push Button start
- 15.1-gallon fuel tank
- Premium Milano leather seats
- Leather-wrapped steering wheel
- Heated 12-way-adjustable front seats (8-way power plus
4-way power lumbar support)
- Power tilt and telescoping steering column
- All-new Head-Up Display
- 8-inch color audio/information screen
- 7-inch On-Demand Multi-Use Display™ with audible and tactile feedback
- Bluetooth® HandsFreeLink®
- XM Radio®
- HD radio
- USB port
- AUX jack
- Auto-dimming rearview mirror
- Power tilt/slide moonroof
- Tri-zone automatic climate control
- Auto on/off headlights
- Leather-wrapped shift knob
- Power door lock/unlock
- Power heated side mirrors with reverse interlocking autotilt down
- One-touch turn signals
- Acura Navigation System with Voice Recognition™
- Next-generation AcuraLink®
- Acura/ELS Studio® Premium Audio System (14-speaker)
- Acoustic glass (windshield, front and rear door windows)
- Collision Mitigation Brake System (CMBS)
- Forward Collision Warning (FCW)
- Lane Departure Warning (LDW)
- Vehicle Stability Assist (VSA) with Traction Control
- Expanded view driver’s mirror
- Multi-angle rearview camera
- Blind Zone Mirror (BZM)
- Blind Spot Information system (BSI)
A line of Acura Genuine Accessories was developed simultaneously with the RLX to provide vehicle personalization for the owner. Like all Acura Genuine Accessories, the RLX accessories are covered by a 4-year/50,000-mile limited warranty if installed by the dealer at the time of original vehicle purchase. Accessories for the 2014 RLX Sport Hybrid SH-AWD include:
- Engine-block heater + transmission actuator heater
- Remote Engine Starter System II
- Body-side molding
- Door-edge film
- Wheel locks
- Deck-lid spoiler
- Rear bumper appliqué
- Car cover
- Illuminated side sills
- All-season floor mats
- Trunk tray
- Trunk carpet mat
- Cargo net
- First aid kit
The 2014 RLX Sport Hybrid SH-AWD is powered by an all-new three-motor hybrid powertrain that combines the power of a conventional V-8 engine with 4-cylinder-like fuel efficiency, along with the performance-enhancing capabilities of torque-vectoring all-wheel drive. As the first-ever electronic Super Handling All-Wheel Drive (SH-AWD) production hybrid vehicle, the RLX Sport Hybrid SH-AWD takes SH-AWD handling performance to a new level.
The RLX Sport Hybrid shares it engine architecture with the two-wheel-drive RLX with P-AWS. The 3.5-liter, 310-horsepower, 24-valve SOHC i-VTEC® V-6 with Variable Cylinder Management™ (VCM™) in the RLX Sport Hybrid adds an idle-stop feature to further maximize fuel efficiency. The RLX Sport Hybrid SH-AWD® is the most powerful Acura production model ever built, with peak output of 377 horsepower. Peak torque to the front wheels is 273 lb-ft at 4,700 rpm (versus 272 lb-ft at 4,500 rpm in the RLX with P-AWS).
The RLX Sport Hybrid SH-AWD uses a total of three electric motors. In front, there is a single 35-kilowatt (47 hp) motor integrated with the 7-speed Dual Clutch Transmission that accomplishes three tasks: (1) supplements the V-6 engine in driving the front wheels when additional power is required, such as in a passing situation; (2) providing regenerative braking to the front wheels; (3) converting engine power to electricity to supplement regenerative braking in recharging the lithium-ion batteries. In the rear, packaged between the rear wheels where a conventional AWD system rear differential is located, there is a Twin Motor Unit (TMU) containing two 27-kilowatt (36 hp) electric motors that dynamically distributes electric-motor torque to the rear wheels, providing both positive and negative (regenerative braking) torque to aid performance and handling. All three motors provide power assist and charge the battery pack with optimal timing in every driving condition.
As a result of the RLX Sport Hybrid’s efficient new 3-motor hybrid powertrain, idle-stop feature and 7-speed Dual-Clutch Transmission, EPA-rated fuel economy is exceptionally high for a sedan in this class at 28/32/30 mpg1 (city/highway/combined). Compared to the two-wheel drive RLX with P-AWS, EPA-rated city fuel economy is up 40 percent and combined fuel economy is up 25 percent. Equipped with new-generation precious-metal catalytic converters, the RLX Sport Hybrid meets stringent LEV III SULEV30 emissions standards (versus the RLX with P-AWS, which meets LEV II ULEV standards).
Acura’s SH-AWD was the first system to distribute power side-to-side between the left and right rear wheels, using “torque vectoring” to create a yaw moment to help the vehicle turn by sending more power to the outside rear wheel during cornering, providing for crisper turn-in, more responsive steering and improved line traceability.
Unlike the mechanical Super Handling All-Wheel Drive (SH-AWD) that has graced numerous Acura models, the RLX Sport Hybrid’s electric SH-AWD operates independent of the gasoline engine; as the two rear-mounted electric motors draw power from the lithium-ion battery pack and dynamically apportion both positive and negative torque directly to the rear wheels. This system provides for more dynamic torque vectoring while eliminating the weight and energy losses associated with a conventional driveshaft and differential mechanism. When cornering, the RLX Sport Hybrid delivers positive torque to the outside rear wheel, much like mechanical SH-AWD, to create a yaw moment.
Unlike conventional SH-AWD, Sport Hybrid SH-AWD can also simultaneously apply brake torque to the inside rear wheel during cornering to further enhance cornering control. In addition, since it doesn’t rely on engine torque, electric SH-AWD can create a larger torque difference between the left and right rear wheels, even during small throttle applications, at low engine speeds and even when decelerating. This substantially magnifies the positive handling benefits of SH-AWD across a much wider range of driving conditions.
The RLX Sport Hybrid SH-AWD system is optimized to provide both outstanding performance and class-leading fuel efficiency. Depending on the driving mode, the system utilizes the V-6 engine, front electric motor and 7-speed DCT, and the twin rear-mounted electric motors and IPU battery pack to provide exhilarating and confidence-inspiring performance while maximizing efficiency. The main drive modes are detailed below.
EV Launch – when launching under light to moderate loads and when there is sufficient battery power, the rear motors alone provide driving power, relying strictly on battery power.
Engine Drive – under gentle acceleration after launch, the front wheels pick up the load using engine power only, while the front motor/generator provides power to the IPU battery pack.
EV Cruising – when cruising at low speeds, the rear motors drive the vehicle using battery power only.
Power Acceleration – under hard acceleration, all four wheels are driven through a combination of engine (front wheels) and the twin rear motors (rear wheels). The front motor also will also assist under hard acceleration from a standing start.
Engine Cruising – when cruising at higher speeds, the front wheels alone drive the vehicle using engine power only while the front motor-generator charges the battery whenever possible using excess engine torque.
Deceleration – when braking or decelerating (throttle lift), the front and rear motors supplement the hydraulic brake system and capture a portion of brake energy to be stored in the IPU battery pack. In regeneration mode, the engine is disconnected to eliminate engine friction and pumping losses to maximize regen efficiency.
AWD – under slippery conditions, all four wheels are driven using both engine power (front wheels) and electric motor power (rear wheels), while the front motor/generator normally provides power to the IPU battery pack.
Cornering under Deceleration – the system simultaneously delivers negative (regenerative braking) torque to the inside rear wheel and positive (driving) torque to the outside rear wheel.
Cornering under Partial Throttle – optimization of front-to-rear and right-to-left torque distribution for improved cornering performance.
Cornering under Acceleration – Negative (regenerative braking) torque on the inside rear wheel transitions to positive (driving) torque for acceleration.
The RLX Sport Hybrid SH-AWD employs an advanced body design to aid dynamic performance, NVH, fuel efficiency and collision performance. The cabin is wide but also extremely aerodynamic, allowing both a roomy interior and a quiet ride as air slips smoothly over the cabin’s flush-mounted acoustic glass windshield and other drag- and turbulence-reducing design details. Beneath the vehicle is a sophisticated series of aerodynamic aids that further smooth airflow.
The 2014 RLX Sport Hybrid with a wheelbase of 112.2 inches (the same as the RLX with P-AWS) is two inches longer than the previous RL model, providing more rear passenger room and improving the ride quality. At 74.4 inches wide, the RLX Sport Hybrid SH-AWD is also a substantial 1.7-inches wider than the RL. Among its competitive set, the new RLX is longer and wider than the Audi A6, BMW 5 Series, Lexus GS series, and Mercedes-Benz E-Class.
Static and dynamic rigidity and rear lateral stiffness are significantly improved. To increase stiffness and rigidity in key areas without increasing weight, 55 percent of the RLX body in white is made from high-strength steel. Hot-stamped high-strength steel is used in key areas for enhanced safety collision performance, with the added benefit of anticipated high scores in narrow offset, side impact, and roof strength tests.
Extensive use of aluminum body components in key areas saves 76.1 pounds compared to traditional all-steel construction. The biggest weight savings for any single component comes from the use of an all-aluminum hood, which saves 19.6 pounds compared to steel. The RLX doors are constructed using a patented new hybrid construction utilizing aluminum outer panels for lighter weight and steel inner panels for stiffness and occupant safety. Altogether, they provide a combination of high stiffness and a weight reduction of 24.3 pounds compared to all-steel doors.
The RLX Sport Hybrid SH-AWD body construction employs several exclusive changes to specific areas of the body to further enhance body rigidity and to provide added protection for the trunk-mounted lithium-ion battery pack. These areas include:
- Front bulkhead, lower
- Rear floor panel
- Rear bulkhead
- Front upper member
- Rear frame
Engineers paid particular attention to reducing interior noise levels, a complicated process that extends to literally every aspect of the vehicle’s design and engineering. To achieve a premium level of interior quietness, the RLX receives an unprecedented amount of acoustic material in key areas. Laminated sound-insulating acoustic glass for all four doors and windshield augment the RLX Sport Hybrid’s isolation of road, wind and engine noise. To mitigate additional noise from the front and rear motors, the RLX Sport Hybrid features additional application of sound deadening materials in the rear floor insulator and trunk floor insulator.
Due to the packaging of the IPU, trunk space is reduced 3 cu.-ft. compared to the RLX with P-AWS, but at 12.0 cu.-ft. is still significantly larger than several competing hybrid models, including the BMW 5-Series (10.6 cu.-ft.), and Audi A6 (10.0 cu.-ft.). The trunk incorporates a 0.4 cu.-ft. underfloor storage area with hinged lid. The trunk also features a model-exclusive trunk net that provides for storage of smaller items in an area suspended above the trunk floor.
Although the RLX Sport Hybrid shares much of its chassis design and components with the RLX with P-AWS, its center of gravity is 8mm lower and its front-rear weight distribution is more rear biased as a result of the trunk-mounted lithium-ion battery pack and rear-mounted Twin Motor Unit (57% front/43% rear versus 61% front/39% rear for the RLX with P-AWS).
In front, the RLX Sport Hybrid SH-AWD features a double-wishbone, lower double-joint front suspension with a hydraulic compliance bushing, high-strength stabilizer bar and Amplitude Reactive Dampers. In back, the RLX Sport Hybrid SH-AWD has a multi-link rear setup that is optimized for a flat ride during cornering, confident turning capability, and a smooth ride in a variety of urban, highway and open road scenarios.
A high-output variable gear ratio belt-type Electric Power Steering (EPS) system provides agile performance in low-speed driving maneuvers such as at intersections, improved overall accuracy and road feel, and superb high-speed stability. A high-rigidity steering column with matching high-stiffness angular bearing contributes to reduce vibration and improved steering feel.
The RLX Sport Hybrid is shod with 19x8J noise-reducing alloy wheels with a model-exclusive 10-spoke design. The special noise-reducing design lowers tire noise by 7-decibels across the audible frequency range.
Consistent with its expanded performance envelope, the RLX Sport Hybrid uses larger front brake discs and larger, two-pot (versus single pot) front brake calipers. The RLX Sport Hybrid also employs an Electric Servo Brake system that uses front motor brake torque to supplement the vehicles conventional hydraulically powered friction brakes and to provide energy to the vehicle’s hybrid battery pack through regenerative braking. The system is designed to operate seamlessly with none of the rough engagement feel of competing systems, while providing an optimal balance between hydraulic and regenerative braking to deliver linear, responsive and natural brake feel and outstanding brake performance.
Another Acura first technology is the RLX Sport Hybrid is its new Reactive Force Pedal, which utilizes an electric mechanism in place if a conventional spring mechanism to dynamically vary pedal force to assist the driver in applying the optimum amount of engine power in any driving condition. For example, when climbing a snowy hill, the Reactive Force Pedal will increase pedal effort to discourage the driver from applying too much engine torque, leading to unwanted tire slip.
The 2014 RLX Sport Hybrid SH-AWD interior combines welcoming five-passenger comfort with by far the most luxury and technology ever offered in an Acura. In the front seat area, a design concept called “dual personal structure” divides the space into areas centered on the driver and front passenger, complimented by a wide center stack and console that is easily accessible to each person. High-end premium elements like a carefully stitched leather instrument panel cover, soft-touch materials, premium finishes and model-exclusive simulated wood-grain accents combine with an intuitive new control layout to create a distinctive environment in tune with this luxury performance sedan’s clearly defined sporting character.
Open the door with the standard Smart Entry system, and you’ll find that passenger space has increased in key dimensions compared to the 2012 RL, with more shoulder room front and rear. Rear seat legroom has been increased a substantial 2.5-inches, moving the RLX to the head of its competitive set in tandem seating distance. Heated 12-way adjustable (8-way power plus 4-way power lumbar support) front seats are standard in the Technology grade, offering all-day comfort along with abundant lateral support for aggressive driving.
Three interior colors are available: Graystone, Ebony, and Seacoast. Stain-resistant Milano leather seats are standard; ventilated front seats and heated rear seats are available with the Advance package.
Standard tri-zone climate control ensures passenger comfort throughout the cabin. Both grades have a front-seat center console that offers 5.8 liters of internal storage space and features a padded armrest lid that slides fore and aft for greater comfort. The lid can open to the left or right, to make access simple for either the driver or front seat passenger. The glove box has a new electric release that can be locked via touch screen.
With the expanded range of standard and available technology features built into the RLX Sport Hybrid, substantial engineering effort was put into making each feature intuitive and easy-to-use. The focal point of the new instrument panel is a large, 8-inch color audio/information screen that provides a range of useful information and access to an array of customizable features including navigation functions.
A 7-inch color On Demand Multi-Use Display™ (ODMD) positioned within easy reach controls the audio system and many other features. The touchscreen eliminates many physical buttons, and is the key contributor to the clean, uncluttered look of the new RLX interior. Dynamic menus clearly display controls for each functional mode, reduce screen clutter and help make operation simple. Audio and touch (haptic) feedback improves usability and control, and helps keep the driver’s eyes on the road.
Acura is known for its technology leadership, and the 2014 RLX Sport Hybrid delivers on this concept. The RLX Sport Hybrid is equipped with the next-generation AcuraLink® cloud-based connected car system, delivering a comprehensive array of media, convenience, and security services via embedded two-way communications and web-enabled devices. AcuraLink® leverages Pandora® interface for streaming audio and the Aha™ by Harman cloud-based interface to provide users with thousands of customizable cloud-based news, information and media feeds. Next-generation AcuraLink® also delivers an array of available, subscription-based, security and convenience features, such as AcuraLink Real-Time Traffic™ featuring freeway traffic and, for the first time, surface street traffic information; airbag deployment notification; stolen vehicle tracking; remote locking and unlocking; security alarm notification; and 24-hour personalized concierge services.
The new generation system is available with three-tiers of service: the Standard Package, which is complimentary for three years, and the Connect and Premium Packages, which are subscriber-based services providing still higher levels of connectivity for the luxury customer.
Exceptional audio performance has long been an Acura hallmark. The RLX Sport Hybrid has two premium audio systems starting with an impressive Acura/ELS® 14-speaker sound system in the Technology grade. Advanced grade models feature a 14-speaker Krell system — with speakers and amplifiers engineered over the last four years by one of the most respected audio companies in world — that sets a high standard in factory automotive audio performance.
SAFETY AND SECURITY OVERVIEW
The 2014 Acura RLX Sport Hybrid is equipped with a long list of standard and available safety technologies. The RLX is anticipated to earn a 5-star Overall Vehicle Score from the National Highway Traffic Safety Administration (NHTSA) and a “TOP SAFETY PICK+” rating from the Insurance Institute for Highway Safety (IIHS), including a GOOD rating in the Institute’s new small overlap front crash test.
Active safety technologies include Vehicle Stability Assist (VSA) with Traction Control, Forward Collision Warning (FCW) and Lane Departure Warning (LDW). Passive safety features include a next-generation Advanced Compatibility Engineering™ (ACE™) body structure, dual-stage, multiple-threshold front airbags, front side airbags, side-curtain airbags with rollover sensors, driver’s knee airbag and front seatbelt e-pretensioners.
The RLX Sport Hybrid is also equipped with Acura’s next-generation Advanced Compatibility Engineering™ (ACE™) body structure, which uses interconnected front frame members designed to absorb and redirect crash energy around the passenger cabin in a frontal collision.