Bob Carter, Lexus Group vice president and general manager, lays it out like this. On the one side there's Mercedes with the S-Class. On the other side, it is BMW with the 7-Series. While some people say that when the first Lexus LS 400 appeared in 1989, it was clearly targeted as being a more value-driven premium car than those built by the Germans, Carter says that at Lexus they're not interested in making a better "German" car, that they're now providing a clearly differentiated automobile. So he says that the LS 460 is a vehicle that is a contender in its own right. Which may be something of an understatement.
Because this is not just another vehicle, but arguably the true successor to the first Lexus, the LS 400, the engineering development team set about in earnest to create a vehicle that would be to the LS 400 what the LS 400 was when it appeared: something extraordinary. So, for example, they developed an entirely new engine family for the car, the 1UR-FSE: the LS models between the LS 400 and the LS 460 had a variation of the UZ engine, which was developed for the first Lexus. This engine is a 4.6-liter, 32-valve, DOHC V8 that provides 380 hp @ 6,400 rpm, which is 102 hp more than is produced in the '06 LS 430. It produces 367 lb-ft of torque at 4,100 rpm, which is 55 lb-ft more than the previous generation. It has an aluminum block, aluminum head, and magnesium cylinder head covers. It features dual injectors per cylinder: direct and port injection for each cylinder to assure that there is the appropriate performance under a number of conditions, be it full load or start up. There's an electrically controlled valve timing system: an electric drive unit (EDU), which consists of a DC motor driver, motor speed controller, and diagnosis output provides input to the brushless DC motor; it controls the intake cam timing rather than the conventional hydraulic control valve. All of this is said to improve engine performance. The camshafts consist of a hollow tube onto which forged lobes are pressed on (the tube is nitrogen cooled and the lobes are heated for this assembly). There's 30° crosshatching of the inside of the cylinders; mirror polishing of the piston pins and crankshaft.
Chief engineer Satoru Maruyamano has been with Toyota for 28 years, 17 of which were spent on transmission engineering. So it is not entirely surprising that he put particular emphasis on the development of a new transmission for the LS 460, the AA80E—an electronically controlled eight-speed automatic. Maruyamano explains that while it would be comparatively straightforward to simply make a larger transmission, he determined that it was important that it be a comparatively compact transmission; the case is approximately the same size as the six-speed transmission that has been used in LS models. Particular emphasis was placed on the development of the case, which is 10% lighter and 30% more rigid than the previous case. Another example of lightening up the transmission: aluminum is used for the sun gear drum and clutch drum; this makes the parts 50% lighter. And as might be expected, this transmission is electronically sophisticated. One consequence of this is that there is a transmission ECU that's separate from the engine ECU. (Though it should be noted that there is a Powertrain Management System that takes input from the ECUs from the engine, transmission, chassis, braking, steering, cabin power, etc., and, based on the driver's throttle input, provides the required engine torque in a manner to provide good fuel economy for the power, reduces shift shock, and reduces drivetrain vibration.)
All of this is leading to a point where someone might say, "Yes, they've done a fine job on engineering a first-rate powertrain." But that's not the startling part. When an engine is assembled for the LS 460, it is put on a dyno and cranked. Not only are there sensors (e.g., accelerometers) used to measure vibrations and other aspects, but a person is in with the engine, listening, feeling, making sure that it is just right. This person is called a "takumi." If he's not satisfied, adjustments are made. (Following that, the engine is mated with the transmission and another test is made under load to check for abnormal sounds or vibrations. Following that, once the engine is in the car, there is another check of sounds and vibrations, both in the cabin and outside the car. And following that, there is another test, this one on a drive.)
Without question, the Toyota Production System has always been about involving people. Yes, there may be fewer people than is the case in conventional mass production operations (despite the fact that mass production operations tend to be far heavier on the automation quotient), but oftentimes during one-piece flow in a cellular arrangement, it is an individual moving the part from station to station. And on the assembly line, the andon cord is pulled by a person who has determined that something has gone wrong. Which leads to the Takumi, the ne plus ultra of craftsmanship, the small group of individuals at that Tahara Plant who are dedicated to assuring that the LS 460s are first-class vehicles in all sensible aspects.
Which leads to an analogy, of sorts: A few years ago, during the Ice Festival held in the town square of Plymouth, Michigan (down the street from the Automotive Design & Production editorial office), I watched two men work on transforming blocks of ice into animals. One man used a small chainsaw (~14 in.) to transform the rectangle into what was to become a bear. The other man, who came from the island of Hokkaido, used an assortment of handsaws and blades to shave the ice into a phoenix. The level of detail—individual feathers were carved—was astounding. There was a machine. And there was the hand, the human touch.
And this is, in effect, is what the LS 460 takumis do. And it is not just checking the engine. They check all aspects of the vehicle. The paint. The body. The fabrics. Everything. Maruyamano admits that this is not the sort of thing that could be deployed in, say, the production of a Toyota Corolla. Yes, it is something that is extreme. But what's important to note is that in an industry that is becoming increasingly oriented toward doing everything in a digital manner, the engineers at Lexus (in 2005 Lexus was organizational separated from the Toyota Division within Toyota Motor Corporation such that it has its own design, engineering and manufacturing centers) believe that it is important to use the human touch.
Although Lexus started out offering Nakamichi as the upgrade audio system for its vehicles, Bob Carter admits that the brand didn't have a whole lot of resonance in the shopping public at large or within the audiophile community. So the company made the switch to Mark Levinson audio systems, which are uniquely available on Lexus products. Generally, the Levinson audio package is available on vehicles that are loaded with options such that according to Carter it seems as though some Lexus customers think that by specifying the "Mark Levinson package" they're asking for the top-of-the-line product. To be sure, there was a specific system engineered for the LS 460. 450 watts from a proprietary DSP amp for Lexus (which features a aluminum housing with a fan to help dissipate heat). Fifteen discrete channels. Nineteen speakers (tweeters and midrange speakers with titanium cones; woofers with polypropylene composite cones). The speakers and the amp are built for Lexus by Mark Levinson in North America. There is 100% audio output testing of all of the amps after burn-in and heat soak. There are DTS 5.1 playback; Dolby Digital 5.1 playback; MP3 and WMA playback.
But here's an even more impressive number: $176,000. That's what it is estimated the Mark Levinson system in the LS 460 would cost if it had been developed for home use. Bob Allen of Lexus College quips that it's as if they're selling an audio system and throwing in a car.
Chief engineer Maruyamano told his development engineers that he wanted the headlamps to resemble crystal. So, one of the engineers used the base of a Baccarat crystal glass as the basis for the projector headlamp lens. But as it turned out, when it was scaled up, it looked like resin, not crystal. So the team actually produced a headlamp lens out of crystal, then ran analyses on its properties (e.g., transparency, refractive index). From that they produced the headlamp for the LS 460.
Speaking of Baccarat, although the name "Lexus," has gained sufficient stature over the last 17 years such that it is sometimes used as an adjective signifying the highest quality, Bob Carter says that to gain a better understanding of luxury, interviews were conducted with executives from companies including Louis Vuitton, Gucci, and Prada. This led to an understanding that it is necessary to have top end products (e.g., the LS 460) in order to set the tone, and then mainstream(ish) products (e.g., the ES 350) that will provide the bigger part of the business. Carter expects that they will sell 30,000 units (of which 65% will be the standard wheelbase models; in keeping with having something at the top of the line, the LS 460 comes in a long-wheelbase configuration, as well, one that increases the wheelbase from 116.9 in. to 121.7 in. and the overall length from 198 in. to 202.8 in.; this facilitates the optional Executive Class Seat package for the LS 460 L, which reduces the number of rear passengers from three to two but gives the right seat passenger, in particular, optimized comfort, including an ottoman leg rest and a massage feature that deploys eight small airbags that are operated by a compressor in the trunk; these two models will be followed in Spring '07 with the LS 600h—a hybrid version). When Carter discussed the launch of the ES 350 (which went on sale in April '06), he said they were anticipating sales of 70,000 units.
"Our engineering team spent four-and-a-half years crafting what would become the LS 460," Maruyamano says. Notice that he didn't say anything about fast time to market or reducing the development time. "In that time we have worked to expand the definition of the full-size luxury sedan in all areas: technology, interior and exterior. Every aspect of the LS—engine performance, handling, suspension, safety—was approached as if we were creating a fine musical instrument."
Time was and is invested in this vehicle. Consider the painting process at the Tahara Plant. Maruyamano says that previously, bodies were prepared by using robotic buffing; the buffing moved up and down along the bodies. But they decided that it would be better to have three axes of movements to assure better buffing of curved surfaces and ends, so they developed six-axis robotic capability. "Six months were spent in developing the robots' control logic to achieve the right amount of buffing force and oscillation," he says. After the buffing is complete, the body is coated. During the paint process, all vertical surfaces are hand sanded twice in order to assure the kind of finish desired. Or consider the leather seating surfaces. They're buffed twice. The total time spent is six hours. This means that the seats are buffed for six times longer than is the case for other Lexus models.
"More than 1,500 people worked on this one vehicle, each one coming to me with their own set of ideas and challenges, and eventually all coming together to build the most Lexus of Lexus vehicles to date," Maruyamano says. No longer in the shadow of Mercedes or BMW, Lexus has come into its own with the LS 460.