TECH OVERVIEW OF THE 2005 IMPORTS

Transcription

1 TECH OVERVIEW OF THE 2005 IMPORTS BY PAUL WEISSLER Cylinder deactivation, direct fuel injection, broader hybrid applications, variable valve lift and timing and several other innovations are described in this year s import report. 20 December 2004

2 Honda Odyssey Subaru Legacy Mercedes-Benz SLK The Year of the Car, it turns out, doesn t apply only to the 2005 domestic cars (see last month s tech report). Import nameplates have their own lists of new offerings, and although some of the technology on the various makes and models is similar, there also are major differences. Subaru has new-generation Legacy sedans and Outback wagons with major new powertrain and chassis designs to go with the new styling. Audi A6 December

3 TECH OVERVIEW OF THE 2005 IMPORTS Honda has a new Accord hybrid and Odyssey minivan, and its Acura line moves the RL further upscale. Volvo has introduced a new S40/V50 series, based on a Ford world platform also used by the Mazda 3, but with a Volvo powertrain and trademark safety features. Audi s new A6 has its first directinjection gasoline V6 for the U.S. market. The Mercedes SLK may be a familiar nameplate, but the 2005 model has the company s first V6 with variable valve timing. It also gets the sevenspeed automatic transmission introduced last year on the E-Class. And there s more, as you ll see. Here s what s coming out of the import camps for This cutaway of a PAX System tire shows the structural plastic support that enables it to run after loss of air pressure. A special bead maintains the joint. The first highvolume production application is on the Honda Odyssey minivan (joining Dodge Viper and Cadillac XLR). The tire also can be repaired with standard patches and plugs. Honda Of immediate interest to independent shops is that the new Odyssey becomes the first high-volume vehicle to have Michelin PAX System (so-called runflat) tires, which have a run-flat structural insert and a special bead attachment. Other vehicles, such as the Dodge Viper, Corvette and Cadillac XLR, use a different technology, which adds stiffness to the sidewalls. According to Michelin, PAX tire punctures can be repaired with conventional patching and plugging, and the tires can be The Subaru Legacy s new 2.5L intercooled four-cylinder boxer turbo develops 250 hp. Engine internals are based on the 300-hp engine in the Impreza WRX Sti, and include variable valve timing. The double-overhead camshafts are belt-driven on this engine, vs. chain-driven on the 3.0L six-cylinder. Photo courtesy Michelin Photo: Paul Weissler mounted and removed with many existing changers with a new adapter kit (available from Hunter, Corghi and Accu-turn at this time). Furthermore, Michelin has distributed to all Honda dealers and designated independent repair shops the Odyssey hatboxes, which are plastic containers containing a complete assembly tire and wheel ready for inflation and mounting. All 2005 Odysseys are equipped with a 255-hp, 3.5L V6, an engine with variable valve timing and variable lift. However, that engine in the Touring and EX versions also is Honda s first with cylinder deactivation. It runs on just three cylinders in deactivation mode, when the rear bank is disabled. This choice was made because the transverse engine s front bank can be cooled more effectively when it s running solo. The method is unique to Honda, which builds on the variable valve lift system using a hydraulic circuit with a dual feed through a threeway solenoid-type spool valve. Normal operation is all six cylinders with variable valve timing and variable intake valve lift, using Honda s threerocker intake valve system with oilpressure-controlled pistons switching the valve operation from individual lift profiles to the rocker with greater lift at high rpm. With cylinder deactivation, the pistons switch the intake and exhaust valves to rockers with zero lift cam lobes. Because cylinder deactivation occurs at relatively low rpm (vs. high rpm for the increase in valve lift), it takes a new oil pumping system to provide the pressurized oil. A three-cylinder engine could be noisy and rough at low rpm, so Honda took two innovative steps front and rear vibration-canceling, electronically controlled, fluid-filled engine mounts and active noise cancellation (ANC). The powertrain computer calculates engine vibration for the rpm and a solenoid-controlled metal diaphragm in each engine mount creates a countervibration against the fluid to cancel the engine vibration. Similar mounts have been used by Lexus and Honda to improve idle smoothness, but the Honda system is the first to work over a wide rpm range. ANC is an out-of- 22 December 2004

4 OVERVIEW: THE 2005 IMPORTS Cap Cast-In The steel main bearing cap (shown separated here in foreground) is cast into the aluminum engine block using a new process developed by Subaru. Steel Cap phase noise broadcast by the sound system to mask any engine booming noise that is not controlled completely by the engine mounts. The counteracting noise also is broadcast as the engine is started and is idling. Does this lead into a change in a technician s thought processes for diagnosis of engine roughness? Obviously, because if it occurs at idle or in three-cylinder mode, it might not be caused by spark plugs, valves, etc., but by a malfunctioning engine mount or even a problem with the vehicle s sound system. Cylinder deactivation is combined with a hybrid electric powertrain system on the Honda Accord hybrid, which uses a 3.0L version of the 240-hp V6. Honda does not produce a true hybrid, because the Civic and now Accord versions (along with the original Insight) do not run on electricity alone. The Integrated Motor Assist provides an acceleration boost for the gasoline engine. But in the real world, our tests demonstrated that the fuel economy is there; the Civic hybrid electric got 45 mpg in mixed driving, mostly highway. The EPA ratings for the Accord V6 hybrid electric are 30 city/37 highway, which are more typical of four-cylinder engine numbers. This model also will be equipped with an electrically operated hydraulic power steering pump, eliminating the belt drive. Acura The new RL is designed to move up to the lower rung of what is now called luxury, i.e., about 50 grand. And although the 3.5L V6 has been boosted 75 hp to 300, it s still not a V8, which is what the higher priced brands use. However, the RL is obviously a luxury model, with all-wheel drive standard. In fact, the version in the RL is called SH-AWD ( SH stands for Super- Handling). That term refers to a rear axle with a gearset and clutch pack that not only distribute rear torque according to traction, but overdrive the outside rear wheel in hard cornering. In fact, virtually all rear torque could go to that wheel, while the inner wheel effectively freewheels. The extra performance comes from an engine that s freer-breathing and higher-revving to develop the peak horsepower (at 6200 rpm vs for the 2004 model), plus variable-flow exhaust, and a compression ratio boost from 9.6 to 11.1:1. Subaru The 2005 Legacy and Outback still have the horizontally opposed ( boxer ) four- and six-cylinder engines, but Photo: Paul Weissler If the chart at right is missing, please circle #14 on the Product Information Card on page December 2004

5 TECH OVERVIEW OF THE 2005 IMPORTS This photo of the Subaru 2.5L four-cylinder engine shows that the battery at the driver s side is angled toward the rear. This is one of many steps Subaru has taken to reduce front-end bias for improved handling. Subaru s six-cylinder engine doesn t have rocker arms, so changes in valve lift occur by locking the inner lifter section (which bears against the valve) to the outer section (which bears against the higher-lift cam lobes). Low-Lift Lobe High-Lift Lobes This view of the Subaru six-cylinder camshaft shows the two narrow lobes (for the high-lift outer lifter section) sandwiching the low-lift lobe. Photos: Paul Weissler aside from the basics (including one of five types of AWD), these are dramatically new vehicles. They re designed to feel slick and drive slick in order to compete against only slightly more expensive AWD models from BMW and Infiniti. The base four-cylinder engine still is 2.5L and develops 168 hp, up a modest 3 ponies from However, there s also an everyday turbocharged, intercooled 250-hp version with variable valve timing that s standard on the Legacy GT and Outback XT. Externally, the only noticeable change in the four-cylinder is use of a plastic intake manifold, but the powerplant is based on the Impreza WRX Sti version, and the new internals go beyond the valve timing. The rear main bearing is a steel form that s cast into the aluminum block, a first-ever design of this type. It s a technique with a purpose: The insert and the steel crankshaft have the same heat expansion ratio, so the clearance remains the same and the engine runs quieter. The flywheel is a dualmass type for improved vibration dampening. The front end, including the engine compartment, was redesigned to reduce weight for improved handling. The front bumper beam and hood are aluminum, and the underhood weight was redistributed. Seemingly small changes, like angling the battery rearward, were among the things that made a difference. A lowered center of gravity also contributes to improved handling on these new Subarus. The engine is mounted almost an inch lower, the front differential about 3 4 in. And even the washer reservoir was lowered, which means now a dipstick is needed to read the level. The Legacy also has a new steering gear with a so-called cannon mount, which holds its position better than the U-clamp it replaced. This is designed to make the steering more responsive. The Outback s optional 3.0L six-cylinder boxer engine was substantially redesigned, which raised it from 210 to 250 hp without a turbo. The big change is variable lift to go with variable valve timing. The H-6 has no rockers, so the 34 December 2004

6 TECH OVERVIEW OF THE 2005 IMPORTS change in timing is performed by twosection lifters (inner and outer sections) and computer-controlled solenoid-type oil pressure valves. In normal lift operation, the two sections are operated by separate cam lobes, but only the inner section (low lift) operates against the valve. For high-load, high-speed operation, the computer opens a solenoid and oil pressure pushes a pin to lock the two lifter sections together. Because the outer section is positioned against a high-lift lobe, the valve now opens further. One of the two intake valves actually has slightly less lift than the other in the low-lift mode. So the incoming air/fuel mix comes in as a thin jet stream. This creates a swirl pattern in the combustion chamber, which improves fuel mixing for better combustion. The Outback also offers the 2.5L turbo Four, which is rated at 250 hp. But the torque curve is different from the naturally aspirated H-6, and the two engines perform differently as a result. Saab If you lift the hood of a new Saab 9-2X, you may think it looks very much like a Subaru. It should. Except for body paneling front and rear and some interior trim, it s based on the Subaru Impreza, with the same naturally aspirated 2.5L four-cylinder (rated at 165 hp) and the 2.0L four-cylinder turbo (rated at 227) as in the Impreza models. The exhaust manifold of the Volvo S40/V50 five-cylinder has a downward slope as part of a redesign to make the engine narrower, increasing safety crush space in a crash. Engine Stop Member Exhaust Manifold Photo: Paul Weissler Volvo The Volvo S40 sedan and V50 wagon are the newest versions of Ford s new world small car platform (the Mazda 3 introduced last year was the first entry), offering strong proof that there s more to a car than the platform. If you didn t know the two cars shared one, you d never be able to tell from their performance and interior design. The new S40/V50 models are actually about 2 in. shorter than their predecessors, at 176 in. overall. The S40/V50 have Volvo transversely mounted five-cylinder engines, either the naturally aspirated 2.4L that develops 168 hp or the 2.5L turbo that develops a hearty 218 ponies. These engines are also used in other Volvo models, but in the S40/V50, there are important differences, typically intended to enhance Volvo s safety image. Most significant is that the engine is much narrower fore/aft by almost 8 in. The exhaust manifold is reshaped to cant downward instead of more rearward, and on turbo-equipped models, the turbo is cast into the manifold. Accessories were relocated to nest more closely to the engine. So don t be surprised if service access on these models is somewhat tighter than others with the same basic engine. Sure, the narrowing stiffens the accessory mountings for a quieter engine, but the real objective was to increase the amount of free length in the compartment for a crush zone in case of a frontal accident. With the extra 8 in., the S40/V50 have as long a crumple zone as larger Volvos. In addition, the Volvo S40/V50 have a U-shaped member across the rear of the powertrain compartment, as a positive engine stop in case of a very severe front crash. There s also almost 3 in. of clearance between the top of the engine and the hood, to give the hood room to crumple in case of a frontal accident. The intake manifold is primarily plastic, but the injectors are mounted in an aluminum section a more rigid, safer location. A tubular beam across the underdash area ties the A-pillars and lower side members together, which is likely to adversely affect underdash access. But at least you know it s there to improve the vehicle s performance in a side-impact crash. There s a six-speed manual transmission standard on the S40/V50 of Volvo s Dashboard Beam This photo of the Volvo S40 chassis shows the engine stop member just forward of the cowl, and the tubular beam under the dash. The beam ties the A- pillars together for better side-impact crash performance. Illustration courtesy Volvo 36 December 2004

7 own design and execution the same one used on the high-performance S60R and V70R models and an optional five-speed automatic. The previous models were strictly automatic transmission. The Haldex electronic AWD is optional. The electrically operated power steering pump runs off the belt drive. The S40/V50 headlamp assemblies have a novel mounting. Instead of having to loosen retaining screws, you simply pull out a wedge sleeve and slide the assembly right out. Audi Audi s new midsize A6 sedan is, as you d expect, a powerful luxury car. But it s also a technologically advanced one, with the first direct-fuelinjected V6 engine sold here. The 3.2L engine (increased in displacement from 3.0L last year) is built on the same architecture as the 4.2 V8. It has a 90 bank angle, so you shouldn t be surprised to know it has a balance shaft. Unlike the five-valve V8, however, it has a four-valve head. Direct fuel injection provides a good balance of performance (255 hp, 243 ft.-lbs. of torque), emissions and fuel economy. It has a 12.5:1 compression ratio, yet runs on 91 octane premium fuel. The injection system is almost diesellike. It s a common-rail type, and the pump is a single-piston design that develops pressures up to approximately 1500 psi. That s not in the diesel class, but is clearly many times higher than for a gasoline engine with port fuel injection. In the Audi A6 3.2L V6, the injectors spray directly into the combustion chambers, a design that improves fuel economy and performance. Although it s a larger car with a larger engine (the 3.2 replacing the 3.0 V6), the mileage figures for the A6 are 19 city/26 highway, vs. 18/25 for the previous model. The 3.2 produces 255 hp (up 35 from the 3.0) and 243 ft.-lbs. of torque (30 more than the 3.0). A wedge sleeve holds the front lamp assembly on the Volvo S40/V50. Lift out the sleeve and the front lamp assembly can be removed, as shown. The A6 Quattro uses a six-speed ZF automatic transmission, with a Torsen center differential built into its rear end. The axles have electronic clutches, so even if only one wheel has traction, the car will not be stuck. Next year, when a front-drive A6 reaches the U.S., it will be offered with the Multitronic continuously variable transmission, which was introduced two years ago on the A4. The A6 gets Audi s first application of adaptive headlamps, an option with xenon lights. The headlamps pivot through turns in response to steering angle and road speed. The car also has keyless entry and starting. Toyota/Lexus/Scion It s a carryover year in the car department for Japan s largest automaker, primarily because of delays in the introduction of the Lexus RX 400h and Toyota Highlander hybrids. They reportedly will be out next spring, and will feature larger versions of the full-hybrid system used in the Prius. However, they ll be teamed with the 3.3L V6 and, as Honda is doing with the Accord hybrid, will be touted as vehicles with the performance of a V8 and fuel economy close to that of a four-cylinder. December

8 TECH OVERVIEW OF THE 2005 IMPORTS There is one new model, however the Scion tc, the sport coupe a small sporty car with a low base price (about 16 grand) and lots of room for personalization. The engine is a 160-hp version of the Camry 2.4L four-cylinder. Four-wheel discs with ABS, a five-speed manual and a/c are standard. Toyota Racing Development will be promoting a dealerinstalled TRD turbocharger to boost output to 200 horses. TRD lowering springs and 18- and 19-in. wheels also will be among the dealer add-on options. And for the impatient, Toyota s next new entry will be the 2005 Avalon, which historically has been a stretched, upscale V6 Camry. Will Toyota move it further away from the Camry? We ll see in February, when the new model is scheduled for introduction. The Lexus SC 430 hardtop convertible gets run-flat tires for 05. The objective was to eliminate the spare tire so there s room for at least a deck of cards when the top is down and folded into the trunk. A Friendly Warning In Infiniti s lane departure warning system, a camera takes a picture of the road ahead, and a computer identifies lane markings. This composite image shows the location of all system components. Jaguar It s basically a carryover year for Jaguar, with one noteworthy exception: a sport wagon built off the AWD X-Type. The wagon is new from the B-pillar rearward, and is available only with the transversemount, 227-hp, 3.0L V6. The X-Type is based on the current version of a Ford European platform, and frontdrive-only models with the 2.5L V6 are available in Europe. It s Jaguar s first-ever wagon, and at 37 grand, it s just $2000 more than the sedan. You re drifting across the lanes, perhaps because you re beginning to doze or are simply distracted. There s a lot of electronics technology in development that could force your car back into lane, but no one has figured out how to positively sort a dozing driver from one who s perhaps moving over intentionally. Therefore, the first lane departure system you ll be seeing is not going to analyze too deeply. Unless you signal for a lane change, it will provide a friendly warning, an inoffensive, lighttoned, three-beep that should alert you, just in case. Offered on the new Infiniti FX45, the system uses a camera to produce a digital image that s analyzed by an electronic control unit. Its software interprets the image to determine lane markings, and even is able to distinguish ghost marking from new ones, rumble strips, HOV lanes, even those raised lane markers called Botts dots (which also may serve as a kind of wake-up call). The system also will go into the MX45 next spring. It s already been used successfully on bigrig trucks in Europe. Suzuki Suzuki is quietly expanding its line. It s adding another Korean-built transverse front-drive car, the Reno five-door subcompact, to compete against the Mazda 3, Ford Focus and Scion sedans. At 169 in. overall, it s 8 in. shorter than the Forenza, with which it shares a 2.0L four-cylinder that develops 126 hp. The top-of-the-line Verona gets a 2.5L V6 rated at 155 hp as standard equipment. Only the Aerio (called a premium compact at 171 in. overall length) and Aerio SX crossover are Suzuki cars built in Japan. Also built by Suzuki in Japan are the Grand Vitara SUV and its stretched version, the XL-7. Suzuki s sales target is 200,000 vehicles by Kia And still another Korean five-door subcompact hits the market for 05 the Kia Spectra 5. If you didn t realize how closely to one another all these cars are spec ed, this one also is a transverse front-drive 2.0L four- Photo & illustration courtesy Infiniti 38 December 2004

9 Illustrations courtesy Mercedes-Benz The new Mercedes SLK 3.2 V6 is a departure from the threevalve, two-spark-plug combustion chamber. It s a chaindriven DOHC four-valve design that provides a horsepower increase from 215 to 272, and improves fuel economy. An AirScarf is a new feature on the SLK. A PTC (positive temperature coefficient) ceramic heater and fan in the seat back blows warm air through the headrests, so the car can be driven comfortably in brisk weather with the top down. cylinder. But at 138 hp, it s the performance leader of the Korean crowd. Overall length is also 171 in. Infiniti A lane departure warning system, which provides a soft chime when the car seems to be drifting across highway lanes (for instance, when a driver starts dozing or even is just inattentive), has been introduced as an option on the 2005 Infiniti FX45. It also will be available on the MX45, coming next spring. A camera takes a picture of the road ahead and sophisticated software analyzes what is seen, picking out lane markings. It s even able to sort out ghosted lanes that are no longer used and focus on the new markings, identify HOV lanes, even Botts dots (the raised inserts used as lane-marking indicators a driver should feel). Unless the driver signals for a lane change, a control computer sounds the chime a better-safethan-sorry strategy. This system was introduced on big trucks in Europe and its effectiveness demonstrated. Mercedes-Benz Unlike Mercedes usual evolutionary approach, the 2005 SLK roadster goes into a lot of new territory for this company. The engine is a 3.2 V6, but very different from the 215-hp threevalve version long used. It s a fourvalve design with variable intake and exhaust valve timing, which develops 272 hp. Surprisingly, it s the first Mercedes V6 with those features (in fact, Mercedes only previous fourvalve was a four-cylinder). The emissions control system features a linear oxygen sensor, which will require different service techniques. The intake manifold has computer-controlled flaps for a two-airflow-path system (a long path for low speed, a short path for high), and socalled tumble flaps, also called charge motion flaps, which produce a tumbling mixture movement into the cylinders for improved mixing and therefore better combustion. That translates into smoother idle and improved fuel economy. Reflecting Mercedes precision engineering, the intake valves have a shaft diameter of just 6mm (under 1 4 in.), so they pose virtually no restriction to airflow. You may think all European cars already have rack & pinion steering, but the new SLK gets it for the first time, replacing the previous recirculating-ball design. And if you think double-wishbone suspension is the only way for a premium car, the new SLK comes with MacPherson struts and a three-link system. The SLK is a luxury car, and when the convertible hardtop is down and the weather turns brisk, an AirScarf can be actuated with the press of a button. Using a PTC (positive temperature coefficient) ceramic heater and a fan in the seat backs, it produces a flow of warm air through the headrests. Visit to download a free copy of this article. December