Pity the poor minivan. Only a few years ago, it was king of the hill. Now it's being replaced in America's car-buying heart by the intimidating sport utility vehicle. This year, carmakers can't seem to crank out new sport utility vehicles fast enough. Shortly after Mercury introduced its Mountaineer, Lincoln now follows with the pricey Navigator. Not to be outdone, GMC this year unveils the Yukon Denali, while the compact Envoy waits in the wings.
But, automakers aren't spending all their time and effort on sport utility vehicles. This year, as in the past three years, engineers are looking ahead. The Partnership for a New Generation Vehicle is making strides toward a "Super Car" that will get 80 miles per gallon. With the new Plymouth Prowler, Chrysler hopes to create a rolling materials test lab that could serve the company for decades to come. And, with its industry-first paperless design of the LH, Chrysler has shown itself and its competitors the future of the design process.
Meanwhile, in a bow to environmental concerns, Ford makes its entry into the electric vehicle market with the Ranger EV.
Asian carmakers are, among other things, focusing on low emissions. Nissan's Frontier pickup, for example, meets Low Emission Vehicle standards, and the 2.3l, four-cylinder in the Honda Accord EX meets Ultra Low Emission Vehicle standards.
Across the Atlantic, European car manufacturers are focusing on engine design. Case in point: Mercedes-Benz will launch many of its 1998 models with the company's first V-6 power plant. It uses an aluminum cylinder block and cylinder heads, as well as magnesium valve covers and intake manifold.
Safety, too, continues to be on the minds of car buyers. That's why every car company has designed their version of the steel safety cage, which more effectively absorbs energy during a crash. Its also why OnStar, the cellular-GPS service from GM, has spread to 24 different car models.
Here are the most significant innovations coming from the U.S., Europe, and Asia, as uncovered by Design News editors.
Style and Substance
LH DISTINGUISHES ITSELF. One of the criticisms of the 1993 LH sedans was that Concorde and Intrepid failed to distinguish themselves as separate vehicles. Chrysler designers eliminated that problem in the 1998 LHs. The new Concorde features a low, wide chrome grille face with an egg-crate texture, reminiscent of classic Ferraris and Aston-Martins. Intrepid, meanwhile, looks more like a Dodge. Its quad-system headlamps are designed under a single cat's eye lens. Distinctive cross-hair grille and round, outboard fog lamps distinguish it as a Dodge.
LINCOLN GOES OFF-ROAD. Once upon a time, luxury car makers introduced luxury cars. This year, luxury-carmaker Lincoln introduces the Lincoln Navigator, a sport utility vehicle. From the outside, Navigator's front bumper fascia and smoothly sculpted fenders give it a muscular look. From the inside, it's pure luxury, with 18-ounce carpeting, a soft-touch instrument panel with buried walnut inserts, and leather upholstery.
PROWLER IS AN ALUMINUM TEST BED. Plymouth gives its Prowler aluminum wheels from CA-based American Racing. Because aluminum's molecular structure becomes highly oriented during spinning, welding a spun rim to a cast spider proves difficult. The material's structure seeks a more random state when heated. That's why the supplier developed a narrow-electron-beam welding technology that precisely controls heat application and ensures part uniformity.
An all-aluminum frame and seat pan saves another seven lbs in the Prowler. Intergram supplies Chrysler's first leather-covered seat produced with the foam-in-place process.
The Prowler's headlamps are actually an integral part of the front painted body panel structure. The show car's flush, saber-shaped headlamps had a strong angle that made it difficult to obtain a legal beam pattern. So engineers used ellipsoid projector-beam technology from Bosch. The technology doesn't require large reflector surfaces, so all engineers had to do was bulge the light housings out from the sides, then make sure that the interior surfaces were properly curved to limit refraction.
SUBARU MAKES A SPORTS WAGON. The new Subaru Forester is similar in size and function to the Toyota RAV4 and Honda CR-V, but unlike either of those vehicles, the Forester meets federal safety and emission standards for passenger cars. Built on the basic Impreza platform--winner of back-to-back World Rally Championships--it shares its all-wheel-drive driveline with the Legacy Outback. Power comes from the company's classic 2.5l, 4-cylinder, horizontally opposed, 16-valve, DOHC engine that pumps out 165 hp at 5,600 rpm and 162 lb-ft of torque at 4,000 rpm. It's Subaru's first all new model since 1992, and the company claims, the first "sport utility wagon" as well.
NISSAN TARGETS THE ACTIVE SET. Attention all doing-it-all, baby-toting truck drivers: Nissan's Frontier is set to roll off the assembly line in Smyrna, TN. The company claims it has the largest standard cargo bed of any compact truck, and is available in both 2- and 4-wheel drive models. Engineering goals included giving the truck a more car-like ride and adding car-like safety features, including dual airbags and a passenger-side airbag cutoff switch for rear-facing child seats.
ACCORD GETS A TRUE COUPE. The new Accord Coupe represents the first time Honda engineers designed the sporty two-door specifically to be a coupe, and not simply a sedan with fewer doors. The Coupe shares almost no interior or exterior components with the Sedan. Both the Coupe and Sedan were developed and tested by Honda R&D in North America, based partly on the response of numerous customer focus groups. Complaints of the previous design focused on it being too sedan-like. Not anymore.
TOYOTA DEBUTS THE CAMRY OF MINIVANS. Internally, Toyota engineers referred to the new Sienna as the Camry of minivans--and with good reason. Built on a stretched Camry platform with a wheelbase of 114.2 inches, 9 inches longer than Camry, the Sienna uses the same 3.0l V-6 engine (putting out 194 hp), 4-speed automatic transmission, and is even built alongside the Camry at Toyota's plant in Georgetown, KY.
Engines That Will
FIREBIRD GETS FIRED UP. Few car owners are more engine-crazy than those who own a Firebird Trans Am. So they should be delighted this year with the introduction of a new 5.7l V-8 engine that delivers more torque and better fuel economy than its predecessor. Known as the LS1 V-8, it generates 305 hp at 5,200 rpm, and 335 lb-ft of torque at 4,000 rpm. The engine's aluminum block features a deep-skirt design that extends below the crankshaft centerline. Estimated fuel economy for a Firebird with an LS1 engine and a six-speed manual transmission is 17 mpg city and 26 mpg highway.
CHRYSLER GIVES BIRTH TO NEW V-6 FAMILY. The new V-6 aluminum-block engines will debut on Chrysler's LH vehicles. The engines reportedly produce more power with less fuel than the engines they replace, burn cleaner, and have the potential to reduce hydrocarbon emissions by 30%. They also will meet Tier 2 federal emission standards and California's Transitional Low Emission Vehicle (TLEV) standards in 1998.
Among the design changes in all three engines: a 26% increase in crankshaft stiffness from optimizing the distance between the main bearings and rod bearings, the size of the main bearings and rod bearings, and the diameter of the cylinder bores. Additionally, engineers achieved a 28% increase in engine block stiffness by incorporating a structural, die-cast oil pan, increasing the number of fasteners (from two to six) holding the main bearing caps in place, and incorporating a structural beam that ties all the main bearing caps together. They also increased the transmission-case stiffness by 14%, and powertrain stiffness by 41%.
Premium seals and gaskets prevent fluid leakage, while cast-iron lined cylinders improve durability. And the block features oil drain passages cast right into the block that speed oil return, even under high-speed conditions. Heat treating the aluminum block makes it stronger than gray iron. Forged-steel, instead of nodular iron, increases crankshaft strength.
All three engines have low-induction restriction, larger throttle body, larger intake valves, and large throat area to support the high flow intake port and chamber.
INTREPID, CONCORDE GET STIFF BLOCKS. The all-new aluminum block, dual overhead cam, 2.7lV-6 engine replaces Chrysler's existing two-valve, cast-iron, 3.3l engine in the 1998 Dodge Intrepid and Chrysler Concorde. Its 200 hp equates to 74.1 bhp/l , and generates 188 lb-ft of torque at 4,900 rpm. Compression ratio is 9.7:1. Incorporating a structural, die-cast oil pan, structural beam/windage tray, and six-bolt main design increases block-stiffness 28%.
Powering the 1998 Dodge Intrepid ES and Chrysler Concorde LXi, the 3.2l , 24-valve V-6 engine is similar in materials and design to its2.7l little brother. With a compression ratio of 9.5:1, output is 220 hp at 6,600 rpm, and 222 lb-ft of torque. The new engine produces more horsepower than the current cast iron, 3.5 l , 24-valve engine.
LHS AND EAGLE GET MORE HORSES. Powering the 1998 Chrysler LHS and Eagle Vision, a new 3.5l engine produces more horsepower than any naturally aspirated V-6 on the market, Chrysler says. It produces 250 hp at 6,600 rpm, and 250 lb-ft of torque. Compression ratio is 10.1:1. Aluminum reduced engine block weight by about 40 lbs as compared to a cast-iron engine block of similar size.
RAM RECALIBRATES. Dodge Ram Pickup's 8.0l V-10 engine gets calibration revisions, including outside temperature data input, to increase power from 295 bhp to 300 bhp and torque from 425 lb-ft to 440 lb-ft.
CHRYSLER BALANCES ENGINES. To reduce engine couple, or tendency to rotate in a circular motion, Chrysler engineers reduced piston mass by as much as 15%. They also reduced tolerances or variation of the rotating components. The coupling effect was minimized by 27% in the 2.7l engine, 13% in the 3.2l engine and 10 percent in the high output 3.5l engine.
Chrysler's new 2.7l engine has an intake-manifold design that improves fuel economy, reduces emissions, and reduces noise. The design incorporates equal length air-flow paths from the throttle body to each of the cylinders.
CHRYSLER TUNES UP PLUG DESIGN. Chrysler's new family of aluminum block engines employs platinum-tip spark plugs that don't erode like conventional plugs. High-voltage secondary coils connected directly to the spark plugs eliminate secondary wires that can deteriorate over time. Both steps result in an ignition system that fires properly every time with 100,000 mile maintenance intervals.
JAGUAR SEDANS GET A NEW V-8. When Jaguar introduced the XK8 sports car in 1997, enthusiasts knew it would not be long before the all-new, all-aluminum AJ-V8 4.0l engine was fitted to the company's XJ sedans. Speculation ends with the announcement of 1998's V-8 powered XJ Series. In addition to the naturally aspirated AJ-V8--capable of 290 hp at 6,100 rpm--the XJ Series features a supercharged/intercooled version of the engine. At 370 hp, the supercharged V8 is the most powerful series production Jaguar engine ever made, developing 387 lb-ft torque at just 3,600 rpm. Jaguar engineers chose supercharging over turbocharging because it provides immediate response to throttle openings and achieves high boost levels at low- to mid-engine speeds. Supercharging increases volumetric efficiency by pressurizing the air as it enters the cylinders.
Two intercoolers, one per cylinder bank, help boost torque delivery across the rev range, and enable maximum torque to be achieved at lower engine speeds. At only 1,600 rpm, the supercharged version of the AJ-V8 is producing more torque than the naturally aspirated engine at its peak.
AUDI ADDS A FIFTH VALVE. Audi's 1998 A4 2.8l offers more power and torque, yet the same or better mileage than the model it replaces. Primary reason, says the German automaker, is the addition of 5-valve technology. Applied to the DOHC V-6 engine, five valves per cylinder plus variable intake valve timing delivers 190 hp at 6,000 rpm. Max torque measures 207 lb-ft at 3,200 rpm. Thanks to the 5-valve powerplant's greater efficiency, mileage of the new model equals or surpasses the previous model year's combined city/highway estimate of 23 mph.
MERCEDES' THREE-VALVE CUTS EMISSIONS. Mercedes-Benz claims its three-valve-per-cylinder technology, employed on the company's new V-6 engine, can reduce exhaust emissions more than 40%--particularly during warmup before the catalytic converter begins to operate. Normally, the converter needs nearly two minutes to heat up before working effectively. The new system reduces exhaust port surface area 30% relative to comparable 4-valve engine designs. This, says Mercedes, dramatically reduces exhaust heat losses between the engine and the catalytic converter. Result: higher exhaust temperature and earlier converter "light-off."
In another development from Mercedes; one less exhaust valve on the new Mercedes-Benz V-6 engine makes room for two spark plugs per cylinder and an offset-phase twin-plug ignition system. Dual ignition allows an extremely lean fuel-air mixture and late ignition timing during warmup. This, in turn, further increases exhaust gas volume and temperature to help heat the catalytic converter more quickly. In addition, the phase-shifted, twin-plug sequence can change after each combustion cycle for extremely precise combustion control.
SAAB DEBUTS ASYMMETRIC TURBO. Arriving on North American shores in the spring of 1998, Saab's all-new 9-5 showcases several "world-first" safety and performance technologies. For example, its optional asymmetric turbo 3.0l engine develops 200 hp and offers 229 lb-ft torque at 2,100 rpm.
Also from Saab, a new-generation Trionic engine management system now adds throttle control to its fuel injection, ignition timing, and turbo boost pressure functions, effectively eliminating any possibilities of turbo lag.
TOYOTA VARIES VALVE TIMING. Both the V-6 and V-8 engines found in Lexus LS, SC, and GS models receive a significant power and torque boost from Toyota's new Variable Valve Timing with Intelligence (VVT-I). It is continuously variable--unlike systems that have two or three discrete steps--and can be programmed to respond to a variety of conditions, such as speed and engine load--unlike strictly rpm-based methods.
| Lexus' continuously variable valve timing (VVT-I) uses engine oil pressure, regulated by a control valve and commands from the ECU, to advance or retard the intake camshaft by means of a helical spline mechanism inside the VVT pulley. |
VVT-I controls the duration of valve overlap by altering the intake valve timing. It consists of three components: an electronic control unit (ECU), an oil control valve (OCV), and intake camshaft timing pulley (VVT pulley). Inside the VVT lie a set of helical splines that can advance or retard the intake cam relative to the exhaust cam. The helical mechanism is driven by engine oil pressure directed by the oil control valve, which responds to commands from the ECU.
The result: the Lexus 4.0l, 32-valve V-8 pumps out 290 hp at 6,000 rpm (300 hp in the sporty GS400), up 30 hp, while torque jumps from 270 to 300 lb-ft at 4,000 rpm (310 lb-ft in GS400).
HONDA, ACURA FEATURE COMPOSITE CYLINDERS. The new 3.2l V-6 in the Acura NSX and 2.2l 4-cylinder engine in the Honda Prelude share more than just the VTEC variable valve timing technology. Both have cylinders (cylinder-block liners on the Prelude) made with a metal-matrix composite technique that Honda calls Fiber Reinforced Metal (FEM), in which a mixture of carbon fiber and alumina is cast into the aluminum when the block (or liners) is poured. Boring after the pouring leaves a tough composite cylinder wall surface with higher wear resistance and better heat transfer than cast iron. In both engines, the additional strength offered by the process allows for closer bore spacing and a smaller engine. In the NSX, the replacement of the cast-iron cylinder with an FEM block allowed engineers to increase the bore of the originally 3.0l engine to 3.2l while reducing weight by 5.28 lbs.
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| To obtain 195 hp from 1.8 l-the highest-horsepower-per-liter ever offered in North America-engineers at Acura made a few changes to the basic Integra GS-R engine. |
NISSAN CUTS TRUCK EMISSIONS. The 2.4l , 4-cylinder engine initially offered in the new Nissan Frontier (3.3l V-6 to be added later in '98 model year) features dual overhead cams and a lower weight than its single-cam predecessor. It's also the first Nissan truck engine to meet California's low emission vehicle (LEV) rating. To get there, engineers designed short-skirt pistons, revised camshafts and crankshaft, and thinned piston rings to cut frictional losses. In concert with these changes, revised valve timing improves low- and middle-rpm torque. Final engine specifications were still to be determined as Design News went to press.
HONDA ACHIEVES ULEV STATUS. Honda is the first manufacturer to develop a production gasoline engine to be verified by the California Air Resources Board (CARB) to meet the Ultra Low Emission Vehicle (ULEV) standard. Available in the new Accord EX, the SOHC, 4-cylinder engine displaces 2,254 cc, uses dual balance shafts to counter vibration, and puts out 148 hp. It produces 80% less hydrocarbon emissions than the average new 1997 car, and achieves this magic through a combination of lean air/fuel mixture, fast warm-up catalytic converter, and software changes to the engine management system. In ULEV trim, it must be coupled to the 4-speed automatic transmission. The same engine in less-strict Low Emission Vehicle (LEV) form powers the Accord DX and is rated at 135 hp. Another, higher-output version of the same 2.3l four (also LEV qualified) appears in Accord EX models and the new Acura 2.3l CL. It produces 150 hp at 5,700 rpm and 152 lb-ft of torque at 4,900 rpm.
MITSUBISHI TWEAKS ITS SIX. The familiar 3.0l Mitsubishi V-6 found in the Montero Sport LS and XLS includes some unique touches, such as a long port-intake runner that improves low-speed torque. The expanded runner gives incoming air a chance to build speed and rush into the cylinders during the intake stroke, the company claims. A new cooling fan reduces drag, and a self-diagnosing alternator can alert the driver to malfunctions. The engine puts out 173 hp at 5,250 rpm and 188 lb-ft of torque at 4,000 rpm, benefiting from an air-flow sensor that uses both a Karmen vortex generator and hot wire to more precisely monitor incoming air mass. Topping off the tweaks are new fuel injectors that resist fuel deposits.
IT'S A HOT-ROD ACCORD. Accord EX and LX models can be ordered with a new 3.0l V-6 built at the Anna Engine Plant in Anna, OH. It's the same engine found in the Acura 3.0 CL, and puts out a healthy 200 hp at 5,500 rpm and 195 lb-ft of torque at 4,700 rpm. The transversely mounted, SOHC engine incorporates Honda's now-familiar Variable Valve Timing and Lift Electronic Control (VTEC) to both broaden the power and torque band for low-end response and high-end performance. The 60-degree V-6 differs from Honda's previous 90-degree designs, making it more compact. The "square" design has a bore and stroke of 86 mm each, for a total displacement of 2,997 cc.
ACURA GETS HIGHEST HORSEPOWER PER LITER. Acura retains the crown for the engine with the highest output per displacement with the limited edition Integra Type R. From just 1.8l, engineers extracted 195 hp at 8,000 rpm, which works out to 108 hp/l. How'd they'd find 25 more ponys than in the already hot Integra GS-R? Some of the changes include: exclusive pistons combined with a compression ratio of 10.6:1; hand assembled, balanced, and matched connecting rods; hand-polished intake and exhaust ports; special lightweight valves with thinner shafts; high-lift, longer-duration cams; and dual intake valve springs with oval-shaped cross section.
Transmissions Geared for Peak Performance
CADILLAC SHIFTS TO ALGORITHM. The Seville's Performance Shift Algorithm combines the best virtues of an electronically controlled automatic transmission with the quicker response and superior performance of a manual gearbox. When a driver steps deeply on the accelerator pedal, or brakes more aggressively, the Performance Shift Algorithm keeps the transmission in the lowest possible gear throughout the maneuver. When the vehicle reaches higher speeds, the system once again selects a higher gear. The system accomplishes all that without any extra shifting or tripping of mode switches.
PROWLER USES RUBBER. Plymouth Prowler's engine output shaft is hard-coupled to the drive plate on the crankshaft flange, and flexible rubber couplings replace u-joints within the propshaft assembly. The rubber couplings partially damp out torque peaks in the rotational direction produced from the engine, preventing the propeller-shaft tube from conducting noise.
| Prowler employs flexible rubber couplings in place of u-joints within the propshaft assembly to partially damp out torque peaks from the engine. |
AUDI'S TIPTRONIC LETS YOU SHIFT OR NOT. The addition of a 5-speed automatic with Tiptronic(R) as the A4's optional transmission gives more control for 1998. Tiptronic, first offered by Porsche, can either be operated as a normal automatic transmission, or it can be upshifted and downshifted manually using a special shift gate. Audi's five-speed manual transmission remains the A4's standard transmission.
SUBARU SMOOTHS SHIFTING. The 5 speed manual transmission, found mated to the 2.5l engine in Subaru's Legacy, Forester, and Impreza, receives several changes aimed at improved shifting performance. The second-gear synchronizer is now a double-cone design, and instead of having the synchronizer ring part of the gear, it is splined to the gear with the synchronizer rings on the inside and outside of the cone. This provides two surfaces to act on the gear and slow it down more easily during shifting, the company says. A double-cone synchronizer was also added to the 3-4 gear set to smooth the 2-3 upshift as well.
HONDA TRANSFERS TORQUE. Honda's Prelude SH introduces the Active Torque Transfer System (ATTS), which uses a combination of vehicle sensors and driver-input information to augment the driver's control of the vehicle when turning. The company claims that with ATTS lifting off the throttle, applying more power, or even braking during a corner will not change the car's line of travel. Unlike a traction control system that limits torque to a slipping wheel, ATTS increases torque to the outside wheel in a turn. It uses information for steering angle, wheel speed, gear ratio, engine torque data, yaw rate, and lateral acceleration to guide a Moment Control Unit to direct hydraulic fluid to the clutch controlling the outside wheel in a turn.
MAZDA DEBUTS HUB LOCK. Mazda's B-Series 4x4 truck features a new pulse vacuum hub-lock (PVH) front axle system, the industry's first use of this technology, the company says. PVH allows the system to be quickly and quietly engaged with no need to stop or back up. The driver can engage PVH at speeds up to 70 mph.
Great Bodies
CATERA WRAPS PASSENGERS IN A COCOON. Safety cages, like the one in the 1998 Catera, help dissipate energy in the event of a crash. Catera employs structural members at the front and rear, enabling it to collapse in a controlled manner and ultimately reduce the forces transmitted to the occupant compartment. The front structure is designed to provide additional protection in an offset crash.
SUBARU NEUTRALIZES NVH. To further cut noise, vibration, and harshness on the Subaru Legacy 2.5 GT and Outback Limited, engineers made numerous small improvements to a combined 27 different areas of the two vehicles. Significant changes include: the addition of urethane insulator blocks to the steering column, heater motor, bottom of the B pillar, and rear seat cushion anchor; increased insulation at the A, B, C, and D pillars; installation of dynamic dampers to the transmission mount; the addition of PVC to the parcel shelf; and, the incorporation of Sundine(R)--a damping sheet material about 0.08-inch thick--to the rear skirt and parcel shelf.
NISSAN STIFFENS THE RIDE. The meaning of Nissan's mystical "Enjoy the Ride" ad campaign becomes clear with the new '98 Altima. Handling is said to be improved through an increase of 20% in chassis rigidity. Engineers put the additional stiffness to use by lengthening the track by 1.6 inches front and rear to improve the car's ride. An evolution, not a revolution, the Altima retains many elements of the original driveline and chassis design. To the four-wheel independent suspension with Nissan's Super Toe Control in the rear, designers added a wider track and reduced-friction shocks and bushings. The car was also run through a 37-step NVH program that addressed even little details in unique ways, such as the aluminum metal-matrix composite steering wheel which transmits less vibration. And instead of conventional steel, an outer shell of bake-hard "dent resistant" body panels now envelopes the new package.
MAZDA DOES, TOO. Through the use of supercomputers for finite element analysis and extensive CAD work, Mazda engineered in 32% better bending rigidity and 43% greater torsional rigidity in the all-new 626. The results are all on the plus side of the balance sheet. The car has improved safety, ride, handling, and reduced NVH, the company claims, compared to its predecessor.
ISUZU OFFERS A LESS RAUCOUS RODEO. For the '98 Rodeo, Isuzu engineers focused on significantly reducing NVH. Their goal: 70 db(A) at 75 mph, about that of a compact sedan. The previous model measured 73 db at this speed, and because decibels are measured on a logarithmic scale, those 3 db represent a 50% reduction in sound energy. Changes to address noise include redesigned door seals, more aerodynamic outside mirrors, and redesigned tires. Foam asphalt sheets were added between the inner and outer dash panels, under the front floor, and inside the wheel wells. Heat hardened sheet was placed over asphalt insulation in the cargo area, and urethane foam was injected into the front A pillars. The engine was modified as well, with the crankcase now made from a more rigid diecast aluminum, the addition of rubber seals for the head and timing-belt covers, and a redesigned cooling fan.
Safe at Almost any Speed
GM SPREADS ONSTAR TECHNOLOGY. OnStar, the combined cellular phone and GPS system, filters down through General Motors this year, reaching 24 different models. The OnStar service helps drivers find their way, as well as remotely unlocking the doors when they lock themselves out of their cars. It also automatically calls an ambulance when the airbag deploys, and tracks cars when they are stolen. It is available on all '98 Buicks, as well as selected Oldsmobiles, Pontiacs, and Chevrolets.
MERCEDES DEBUTS SMARTER BRAKES. Even experienced drivers may not apply full braking force in emergency situations. An electronic brake-assist system, debuting on many '98 Mercedes-Benz models, recognizes when the brake pedal is being depressed quickly, and reacts automatically. Integrated sensors monitor brake pedal movement. If they read signals which clearly mean an emergency, the electronic control module triggers a solenoid valve on the brake booster for full braking. Since the system is networked with Mercedes' ABS anti-lock brake system, the wheels will not lock. Normal brake control resumes as soon as the driver eases up on the pedal.
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| Electronic brake-assist system shortens emergency stopping distances 45%. |
SAAB DISTRIBUTES BRAKING FORCE. The new 9-5's brake system incorporates electronic brake force distribution that comes into effect under hard braking before the ABS is activated. Purpose: automatically maximize the grip available at each wheel independently to reduce stopping distances.
SUBARU STEERS TOWARD SAFETY. Subaru's new Forester receives several steering modifications that set it apart from the company's other vehicles. The steering column has a new collapsing mechanism that substitutes an expanding plate design for the previous steel ball/drop capsule. And the toe board support for the column has an additional resin cup mounted to the column for better collision response. Not driven by safety, but rather NVH and performance, the steering system also receives a rubber coupling in the shaft universal joint to reduce noise over bumps, and the power steering pump was changed to reduce impact on engine load with rpm. Engineers added an internal cam that reacts to engine speed and changes discharge capacity to suit the conditions.
LEXUS DEVELOPS A SKID ARRESTER. Lexus LS, GS, and SC models introduce a new Vehicle Skid Control (VSC) system that helps avoid skids and spins resulting from understeer or oversteer conditions while cornering. It draws information from half a dozen sensors that measure six parameters: yaw rate, acceleration, steering angle, brake pressure, wheel speed, and throttle opening. An electronic control unit (ECU) processes the information from these inputs and, should it determine that the vehicle's direction does not correlate with the driver's input, adjusts engine output or brakes individual wheels to apply a moment to the vehicle that keeps the vehicle stable and prevents it from spinning. A buzzer and on-dash warning light inform the driver when the system has intervened.
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| Lexus Vehicle Stability Control system reduces the danger of lateral skids through active control of the brakes and engine output. It reads inputs from both the driver and car, including pedal and steering inputs, and yaw and lateral acceleration. |
SUBARU GIVES AIRBAGS MORE BRAINS. The SRS (supplemental restraint system) on the '98 Subaru Legacy receives two new front sensors to help the electronic control module determine if the front airbags should deploy. Called the Satellite Discriminating Sensors (SDS), these "crush zone" sensors are one way auto makers are trying to ensure that the airbags only fire when needed. The SDS provides a signal that tells the ECM if a frontal collision is high or low impact. The system does not affect deployment rate, only its sensitivity and ability to discriminate between events that need an air bag and those that don't.
TOYOTA TAMES THE 'GUILLOTINE' DOOR. An interlock full-open stopper prevents both the sliding doors on the Toyota Sienna from closing under their own weight, addressing the "guillotine" phenomenon minivan owners sometimes confront when parked on a hill. Actuating either the inner or outer door handle releases the interlock and allows the door to close. A similar half-open stopper prevents the driver-side sliding door from encroaching on the fuel-filler area when the fuel-filler door is open. Mid year, a power-operated passenger sliding door will be available as an option. It will include sensors which automatically retract the door when an obstacle blocks its path.
MAZDA ADDS TRACTION CONTROL. Traction control, once the province of upscale, luxury cars, has found its way into everyman cars, such as the Mazda 626. Standard on all V-6-equipped models, the electronic system uses wheel-speed sensors to detect wheel spin and then automatically reduces engine output by adjusting fuel delivery and spark timing. A nice touch that can prove useful in the snow: The driver can override the system with a push of a button on the dash.
Electronics Advancements
CADILLAC RADIOS TO GIVE ELECTRONIC DATA. Taking a cue from the European market, Cadillac this year offers the radio data system (RDS). RDS is an FM-based technology that enables broadcasters to silently deliver a 1,200 bits-per-second data stream along with conventional audio content, allowing users to see the station's call letters, type of programming (jazz, country, etc.), song titles, and artists' names.
BUICKS BECOME OFFICES ON WHEELS. Many computer aficionados would love to plug their computer into their car, if only there were an easy way to do it. This year, Buick's Park Avenue offers that capability. A Convenience Console turns the vehicle into a rolling office. The console includes a center armrest, voice-activated cellular phone pre-wiring, flip-up writing surface, storage area for pens and pencils, and dual auxiliary power outlets to plug in accessories, such as portable fax machines and computers.
TOYOTA USES ABS TO CHECK TIRES. Toyota engineers took a shortcut method of detecting an underinflated or leaking tire on the new Sienna minivan. Instead of putting pressure sensors in each wheel, they deduce the inflation information from the ABS wheel-speed sensors. An underinflated tire rotates more slowly than a properly inflated tire, and by comparing the rotational speed of each wheel against the others, the system can tell if one is low. No absolute pressure readout is possible, but a low-pressure warning light alerts the driver to check the tires.
Technology Potpourri
FORD ADDS ELECTRIC VEHICLE. The Ranger truck just got an electric cousin. The Ranger EV uses a 39-unit, 8V lead-acid battery pack and a 90 hp three-phase ac induction motor for power. It accelerates to 50 mph in 12.5 seconds and has a top speed of 75 mph. Payload rating is 700 lbs, and EV's maximum range between charges is 58 miles when the heater and air conditioner aren't in use. The first electric vehicle manufactured by Ford, Ranger EV qualifies as a Zero Emissions Vehicle.
SAAB ADDS SOME PLEASERS. Standard equipment on the Saab 9-5 includes Saab's Active Head Restraint System, designed to limit head movement during rear-end collisions; the car industry's first ventilated front seats; six high-pressure jet windshield washer nozzles; and an automatic audio volume control that compensates for background noise according to the chosen setting, not just vehicle speed.
MERCEDES HAS SOME KEY FEATURES. Mercedes-Benz introduces the industry's first electronic key in its 1998 CLK coupe. Designed to respond to an infrared data signal sent by the car, the "key" unlocks the steering electronically, switches the ignition circuit on, and operates the starter.
"Parktronic" from Mercedes-Benz alerts drivers when they get close to other vehicles or obstacles during parking. The system uses high-frequency sound waves to sense objects close to the front or rear bumpers.
Low-friction silicon-aluminum cylinder sleeves on the new Mercedes V-6 powerplant reduce piston ring spring tension 50%. They also save more than a pound when compared to conventional iron sleeves.
HONDA EV RELIES ON NiMH. Nickel-metal hydride batteries (NiMH) provide the energy for the Honda EV Plus electric vehicle. Said to offer about twice the energy density of lead-acid cells, the 24 12V cells provide the EV Plus with a claimed 60-80 miles between charges in real-world driving, and an EPA rating of 100-miles city and 84 miles highway. Recharge time is 6-8 hours using a conductive 220V system and "substantially longer," Honda says, with the 110V system. A liquid-cooled, permanent-magnet, dc brushless motor managed by a PWM (IGBT) controller drives the vehicle, putting out a continuous 66 hp from 1,700 rpm to 8,750 rpm,and a notable 203 lb-ft of torque between 0 and 1,700 rpm. Through its single-speed transmission, the spunky city-oriented car hits 30 mph in 4.9 seconds, though 60 mph takes a less than racy 17.7 seconds.