WHAT IT IS—& MUST BE. The 2006 Lexus IS is a sport sedan that is available in two versions, the IS 350 and the IS 250; both of the numeric classifications being predicated on engine displacements of the two all-new V6 engines, 3.5 liters and 2.5 liters. This is a new model, replacing not only the 2001 model IS 300 in the U.S. but all of the other variants available in Japan (where the model was known as the "Altezza"), Europe, Australia, and New Zealand. In other words, the new IS is a "world" IS. What's interesting to note about the new one is based on observations made by Isao Kanehara, assistant chief engineer, Toyota Motor Corp., and Bob Carter, Lexus Group vice president and general manager, about the previous one. Kanehara: "I think it is fair to say that the current IS never fully delivered what we consider a total Lexus experience. Some of what we now call 'Lexus Musts' were missed." Carter, after echoing the lack of delivering on the "Musts," described the outgoing model as "a single-dimensional vehicle with an enthusiastic, yet narrow, band of appeal: young and fun with more sport than luxury," and went on to admit that the vehicle was "selling at a rate of less than 1,000 per month." For the '06 model he is talking about "a sales plan that will increase by more than 600% to more than 40,000 units per year."
Clearly, there must be a whole lot of "Musts" to achieve that number of cars.
So what is a "Must"? On a fundamental level, Kanehara described it as "a baseline of excellence," something that is, in effect, made up of plenty of elements, some of which are comparatively small—e.g., the feeling and responsiveness of the steering wheel; the stitching on the leather seats—but all of which add up to, ideally, more than the sum of the parts.
THE COINCIDENCE OF CONTRASTS. Another way that the "Lexus Musts" are fulfilled is through the realization of a concept that was first set forth by Ichiro Suzuki, chief engineer of the first Lexus, the LS 400: "this yet that." Specifically in the case of the new IS, noted Paul Williamsen, product education manager, University of Toyota:
- Great high-speed handling yet pleasant ride
- Fast and smooth yet low fuel consumption
- Super quiet yet light weight
- Great high-speed stability yet great Cd
- Distinctive styling yet great aerodynamics
- Warm yet functional interior.
- The way these Musts are engineered takes various forms.
HANDLING IT. The high-speed handling and pleasant ride is essentially predicated on a suspension design developed for the Lexus GS (see Lexus GS: Talking Performance And Technology). However, because this is a dimensionally different vehicle, it was necessary to make some adjustments to the multilink suspension (the IS used to have a double-wishbone setup up front): because the hood line is lower on the IS vs. the GS, the front suspension is 20 mm shorter on the new car. The monotube shock pistons are bigger, however: 45 mm vs 40 mm (the GS, incidentally, has double-tube shocks). In the front of the IS, there are liquid-filled bushings at the rear of the lower control arms to reduce the NVH. What's more, aluminum hub carriers reduce unsprung weight while improving the control of suspension motion and providing more compliance in impact damping. There's electric power steering (EPS), which actually provides superior steering feel thanks to computer-controlled power assist. Essentially, there are two torque sensors, one mounted to the steering column main shaft and the other mounted to the pinion shaft. These two signals are used to determine the turning speeds and the torque across the torsion bar between the main and pinion shafts, which is then, in turn, used by the EPS' controller to determine the necessary amount of steering effort for a better steering feel. The car comes with 17-in. wheels standard.
POWER ALL AROUND. There are two new V6 engines developed for the cars, the 4GR-FSE 2.5 liter and 2GR-FSE 3.5 liter. Both are all-alloy, ULEV-II, 24-valve, DOHC with dual (VVT-i)I, direct-injection engines. That's right: direct injection. There is a fully electronic controlled common rail system with slit-nozzle injectors that are mounted in the cylinder head between each pair of intake valves. Slit nozzles? Yes, instead of round holes, there is a slit that produces a twin fan-shaped fuel spray pattern that is more widely dispersed than is ordinarily the case, which helps in the optimization of the mixture of air and fuel. This, in turn, contributes to improved power and better fuel consumption. As regards power, the 2.5-liter engine provides 204 hp @ 6,400 rpm and 185 lb-ft of torque @ 4,800 rpm; the 3.5-liter provides 306 hp @ 6,400 rpm and 277 lb-ft of torque @ 4,800 rpm. (The 3.5-liter engine uses both direct- and port-injection strategies for improved performance.) In addition to which, because the IS is a performance sedan, it offers six-speed transmissions. That's what's fundamental nowadays to that class of cars. Being Lexus (in the Passionate Pursuit of Musts), there is a sense of overachievement in that there are three new automatics: one for the IS 350 and two for the IS 250 because this vehicle is not only available as a rear-wheel-drive model, but all-wheel-drive (AWD), as well. As if three new automatics—all of which offer sport shifting, either via the shift lever on the console or by using paddle shifters behind the steering wheel—aren't enough, because this is a sports sedan, there is also a new six-speed manual gearbox for the IS 250 RWD. A word about the AWD IS 250. It is a system with a default torque split of 30% front, 70% rear; based on either detected wheel slip or—perhaps more likely—wide-open throttle conditions, it can have a 50:50% split. Dimensionally, the five-passenger IS has a wheelbase of 107.5 in.; a length of 180.1 in; a width of 70.9 in.; and a height of 56.1 in., unless it is the AWD version, which is 0.6-in taller. The curb weight ranges from 3,435 lb. for an IS 250 with an automatic transmission to 3,651 lb for an IS 250 with AWD.
TALKING DESIGN LANGUAGE. This is the second (following the GS) global Lexus model which has a design based on the so-called "L-Finesse" design language. Kanehara uses the words "simplicity, contrast, and dynamism" to characterize the attributes of L-Finesse. Not only are the exterior surfaces taut and sleek such that there is flushness between the sheet metal and glass, there is even what Williamsen described as an "air kicker" molded into the lenses of the taillights: its purpose is to move the air so that it doesn't go to the drag area formed in the rear fascia by the license plate indentation. Inside, the L-Finesse forms continue, such as with the S-shaped "sword slash" form on the door panel (over, down and out from the arm rest) to the driver-oriented cockpit. Whereas in the previous IS the wood trim was laminated to a fiber-reinforced plastic backing, they've upped the material to aluminum. There are three separate pieces of wood deployed for the IP and center console; each of these functional pieces is handled by a different supplier. Williamsen says that the Toyota Production System helps assure that the right pieces arrive so that the wood grain is matched for each vehicle. Another assurance takes the form of digital coding on each of the pieces of wood. Inside lighting is provided by a combination of LEDs and micro-incandescent lamps. The automatic climate control is based on neural net technology; it derives input from a number of sources, including a humidity sensor and a smog sensor (which detects the level of hydrocarbons in the incoming air and automatically (1) reduces the amount of air intake and (2) increases the amount of air exhausted from the cabin). Smart key technology is standard; engine start/stop is performed through a pushbutton on the dash.
MAKE IT. Because Lexus executives are planning on a relatively significant number of sales, the IS models will be produced in two Japanese plants:
- Tahara, which builds the LS, GS, and IS models on the same line
- Kyushu, which also builds the Lexus 400h and RX 330 models.
All of the IS vehicle will be test-driven after production. "The proof is in the driving," Williamsen noted with a smile.