Building a Better Ute - Toyota Motor Corp - Brief Article

Automotive Manufacturing & Production, April, 2001 by Gary S. Vasilash

While some vehicle manufacturers are railing against unfortunate economic conditions that are causing their sales to fall, Toyota has methodically continued to do what it does best: produce remarkable motor vehicles. In January, when announcing overall U.S. sales for 2000, wherein Camry became the best-selling car in America for the fourth year in a row, Jim Press, then-Toyota Motor Sales (TMS), U.S.A., executive vp (five days later, it was announced "chief operating officer" was added to his business card), stated, "Last year was great; this year will be merely good." One of the ways that they are working to make it at least good is by increasing the Toyota share in trucks. Don Esmond, Toyota Div. senior vice president and general manager, has announced that their objective is "a leadership role in the North American light-truck segment." To that end, Toyota has bolstered its line up in the truck arena, especially in the sport-utility vehicle segment. It has long had the famous Land Cruiser and the popular 4 Runner. The RAV4 really kicked off the small, car-based SUV segment. Late last year the giant Sequoia rolled out of the Toyota plant in Princeton, Indiana. And most recently, it launched a new mid-size, unibody SUV, the Highlander. The Highlander is not meant to cross the Rubicon Trail. It does, however, perform quite nicely on Ann Arbor Trail (or whatever your local trail-suffixed surface street may be). As Esmond pointed out, "For buyers seeking the real-deal in traditional mid-size SUV performance, with a bias toward rugged use, we have 4Runner. For buyers demanding the image and versatility of an SUV, but who prioritize the ride, handling and comfort of a sedan, we have Highlander."

One characteristic consistent in contemporary Toyotas is that engine noise is such that there are undoubtedly many people who have attempted to start already-running engines. The Highlander ups the ante for Toyota four-cylinder engines in the way that engine noise is reduced. The 2.4-liter 2AZ-FE engine developed for the vehicle uses two balance shafts to offset the secondary harmonic imbalance of the four-cylinder configuration. Paul M. Williamsen, Curriculum Development manager, University of Toyota (Torrance, CA) explains that Toyota has long used two balance shafts in the 2.2-liter four-cylinder engine available in the Camry. However, in the Camry engine there is a steel gear system used between the primary and secondary shafts: "The gears must be very precisely set up to control lash so that you won't have a low-speed whine." But with the Highlander they have made a material switch with great advantage: a plastic gear set in place of steel. They've calculated that this reduces gear noise by 100%--or thre e decibels--compared with the previous design, and reduces total friction by 50%. What's more, Williamsen points out that the resin gears, which are tight-fitting without adjustment, simplify things in that the balance shafts are inside the crankcase, and one certainly doesn't want to have to make modifications to things in there. (The Highlander is also available with a 3.0-liter V6, which doesn't require this setup.)

The four-cylinder engine, which produces 155 hp at 5,600 rpm and 163 ft-lb. of torque at 4,000 rpm, has a cast-aluminum block with cast-iron cylinder liners. Not surprisingly, pistons are made in one size to simplify assembly. What isn't aluminum on the engine is the intake manifold, which is produced with a fiber-reinforced plastic.

Williamsen points out that compared with cast aluminum, the plastic manifold is lighter and quieter. In terms of production, he explains that the manifold comes out of the mold with a better finish. And there is even a safety benefit: in the event of a front crash, the plastic manifold is a "crushable" component. The aluminum manifold is not as forgiving.

Speaking of aluminum, Williamsen says of one component on the Highlander: "I'm staggered by it." it is the front bumper reinforcement. A custom aluminum extrusion that bolts to the front frame rails. It is a piece that is typically made out of a ferrous material. The rear bumper reinforcement is also an aluminum extrusion, but it has a steel tube inserted into its center to accommodate the spare tire well.

Steel plays its role in the Highlander. Most all major body panels (excepting, for example, the roof) are galvanized or galvanealed steel. In producing the body side, Williamsen explains, Toyota makes use of tailored blanks, so as to achieve strength in the door pillars to hang the wide-opening doors on the vehicle. He cites an interesting use of steel: on the optional towing package there is a water-to-oil oil cooler. It's a brazed stainless steel oil cooler. Williamsen says, "Any engineer with tell you you can't braze stainless steel. That's what's so cool about it."

There is extensive use of recycled and recyclable plastics on the vehicle. The bumper covers interior and exterior door trim are produced with a material called "TSOP," which originally stood for "Toyota Super Olefin Polymer;" it is a recycled and recyclable plastic that is capable of holding color and texture better than other plastic materials of that type; Toyota, Williamsen says, is making the formulation open for use by other automakers, so the "T" in "TSOP" now stands for "The."