Toyota Wants Improvement for IC Engines, Hybrids for Lexus

Special Report

Japanese Powertrain Strategies

Part 1

All Options Open in Japanese Future Powertrain Development

Part 2

Toyota Wants Improvement for IC Engines, Hybrids for Lexus

Part 3

Honda Plans for Clean Diesels, Affordable FCVs

Part 4

Nissan Strategy: Expand CVT Use, Re-Examine Diesel

Part 5

Mazda Powertrain Keeps Eye on Rotary

Part 6: April 30

Mitsubishi Rolls Dice With EVs

Second in a 6-part series exploring powertrain strategies for Japanese auto makers.

TOKYO – By 2010, Toyota Motor Corp. intends to completely revamp its gasoline engine and transmission lineups, while simultaneously reducing the number of engine variants – both gasoline and diesel – to fewer than 25 worldwide, from its current 30.

The auto maker’s new gasoline-engine portfolio, comprising more than a dozen variants, will incorporate such technologies as variable valve timing for both intake and exhaust valves to improve fuel economy and substantially reduce emissions.

Meanwhile, continuously variable transmissions will become Toyota’s chief transmission technology for compact and midsize passenger cars.

In 2006, Toyota produced some 8 million engines – 7 million gasoline and 1 million diesel units sourced from 12 manufacturing sites in North America, Europe and Asia.

Its powerplants range from a 1.0L I-4 (built by Daihatsu Motor Co. Ltd.) for the Vitz, Belta and Yaris to the 5.7L DOHC V-8 for the new Tundra pickup truck, which is produced at the auto maker’s 4-month-old U.S. plant in San Antonio.

In the conventional engine field, Kazuo Okamoto, who oversees Toyota product development, expects further improvements in direct-injection gasoline (DIG) technology.

“In the future, we will see more combination port-injection/direct-injection units,” he says.

Witness the dual-injection design adopted by the 3.5L DOHC V-6s developed for Toyota’s Lexus IS 350 and GS 450h models and the all-new 4.6L DOHC V-8 powering the LS 460 and LS 460L, top of the line in the auto maker’s luxury brand.

Toyota sells about 200,000 DIG powerplants a year, mostly in Japan, although demand has begun to curve upward in the U.S. and Europe.

“Certainly sales will increase,” Okamoto says. “But cost is still relatively high. Thus, direct-injection (gasoline) engines will mainly find use in upscale cars.” Toyota currently has five distinct DIG engines in its lineup.

Toyota plans hybridized variants of all Lexus models, such as this HEV version of its LS 460 flagship.

The executive says DIG technology will be instrumental in meeting Euro 5 emissions standards in 2010, while senior engineers in Toyota’s powertrain group hope to lower costs so the technology can be employed for gasoline engines in Camry-class cars.

The auto maker’s new 4.6L DIG V-8, used for the LS 460 and LS 460L, is best in class for both fuel economy and acceleration, Toyota says.

A 5.0L variant has been joined with Toyota’s Hybrid Synergy Drive system to power the soon-to-launch Lexus LS 600h. High on the list of the engine’s advanced features is electronic intake valve timing, an industry first.

And while the auto maker has yet to announce plans to sell a diesel-powered vehicle in North America (unlike rivals Honda Motor Co. Ltd. and Mitsubishi Motor Corp., both of which say they will introduce North American diesels), Toyota’s European engines will increasingly incorporate its advanced emission treatment system called Diesel Particulate NOx Reduction.

The DPNR system currently is installed in the Lexus IS series and upper grades of the Avensis, RAV4, Corolla Verso and Auris. In Japan, DPNR cleans diesel-engine emissions for the Toyoace and Dyna trucks.

Due to still-high system costs, DPNR-equipped vehicle sales are relatively small at about 70,000 units annually. As an interim step until costs come down, Toyota began equipping lower-grade models with diesel particulate filters from the middle of last year.

All but one Toyota diesel-powered vehicle in Europe, the 1.4L Aygo, is equipped with either DPNR or a diesel particulate filter. Management expects half of Toyota diesel vehicles sold in the market to be equipped with the DPNR system by the end of the decade.

In 2006, Toyota sold 438,000 diesels in Europe, 16% of which were equipped with DPNR; most of those were built at the auto maker’s Walbryzch, Poland, plant.

Meanwhile, the auto maker has adapted all gasoline engines in its range to run on 10% ethanol (E10). And this year it plans to introduce a model in Brazil that runs on 100% ethanol (E100).

At the North American International Auto Show in Detroit in January, management confirmed plans to introduce an 85% ethanol flex-fuel Tundra pickup truck in 2009.

In the high-profile hybrid-electric vehicle segment, Toyota plans to double model offerings over the next five years to about 15, from seven today, and hopes to boost annual production to 1 million units, more than triple last year’s 312,000 total and an estimated 10% of global sales by the auto maker.

For that to happen, Toyota must further reduce HEV system cost.

Just how much, Okamoto won’t say, but others in Toyota’s research organization confirm the auto maker is targeting 50% cost cuts by 2010, from today’s approximately $2,500 for the Prius system (including the battery module) to $1,250. The next-generation Prius is due in late 2008 or early 2009.

“Think about hybrids like any other technology when it is new,” says Okamoto. “Televisions, DVDs, other consumer electronics – when they first came onto the market, they were prohibitively expensive.

“Then costs came down over time. Notebook computers are another example. They perform like mainframe computers of the past. No one would have thought this possible when they came out – and to be affordable, no less. We believe that hybrids will follow the same trend line.”

The research executive says Toyota has no plans to offer HEV variants of all light vehicles it produces, but will introduce the technology throughout its Lexus product range.

“We want to change the (Lexus brand’s) concept,” he says. “By using hybrid technology, not only are emissions levels and fuel economy improved, but acceleration and drivability are significantly enhanced. We believe that cars eventually could become more like jetliners in terms of driving feel.”

Nor does Okamoto believe there is any merit in pursuing so-called “mild” HEVs – those employing an electric motor to boost power but unable to drive the vehicle independently.

He says “full” HEVs, which can be propelled either by the internal-combustion engine, the electric motors, or both, offer more value in enhancing fuel-economy.

Toyota currently produces one mild HEV, the limited-volume Crown Hybrid. Monthly output: fewer than 15 units.

Meanwhile, Okamoto is noncommittal about whether the auto maker will introduce a hybridized fullsize SUV and pickup truck in the Chevrolet Tahoe/GMC Yukon class, both of which are due from GM later this year.

“We’ll think about it,” he says, although analysts believe an HEV Tundra pickup, to be built at Toyota’s San Antonio plant, is in the pipeline.

The executive says Toyota has no plans to produce the hybrid Lexus RX 400h at Toyota Motor Mfg. Canada Inc., where the base model RX 350 is assembled.

Nor is Toyota likely to build an HEV in Europe until after 2010. “We must first boost standard car production, all types, to more than 1 million units,” says Okamoto.

In 2006, Toyota produced 808,300 cars in Europe, representing nearly 80% of its sales in the market.

On the HEV battery-technology front, Toyota raised its stake in Panasonic EV Energy Co. in October 2005 to a controlling 60%, from 40% when the joint venture was established in 1996.

Okamoto says Toyota already had a strong technological base in nickel-metal hydride (the main chemistry used in its HEV batteries) when it teamed with Matsushita Electric Industrial Co. Ltd. and Matsushita Battery Industrial Co. Ltd., but had little experience in battery production.

“We now do,” he says.

Will lithium-ion formulations eventually replace NiMH?

“That’s the general direction,” says Okamoto. “But we are still far short of achieving the required performance, particularly with respect to reliability and cost.”

Toyota first adopted a Li-ion battery for the 2001Yaris for the car’s “stop-and-go” HEV system.

The auto maker also used a Li-ion battery pack for the Fine X, an experimental fuel-cell vehicle (FCV) that debuted at the 2005 Tokyo Motor Show, from which are driven four in-wheel motors. No details were provided other than that Toyota has targeted a 300-mile (483-km) range for the model.

Meanwhile, Okamoto does not expect FCVs to be more than niche products for another 20 or 25 years.

“The real test will come when regular consumers can afford them,” he says. “For that to happen a comprehensive network of (hydrogen) fueling stations must be in place. And that can only happen with government support.”

At last October’s International Battery, Hybrid and Fuel Cell Symposium in Yokohama, Toyota unveiled a new 5,076-psi (350-bar) hydrogen storage tank for the Fine-X.

By incorporating a titanium-based metal-hydride core, the auto maker succeeded in doubling the tank’s storage capacity. To date, Toyota has leased 17 FCVs in the U.S. and Japan.

In the transmission sector, Toyota’s focus will continue to be on automatic transmissions and CVTs.

“For the time being, we are not seriously considering dual-clutch (automated manual) units,” says Okamoto, in reference to a technology being advanced by Volkswagen AG and several transmission suppliers.

Toyota’s main transmission supplier, Aisin AW Co. Ltd., has been the leading supplier of 6-speed conventional automatics since marketing the industry’s first 6-speed unit in 2002.

In addition to supplying upscale Toyota and Lexus cars such as the Crown Majesta, Mark X, GS 430 and SC 430, Aisin AW supplies 6-speed gearboxes to BMW AG for the Mini Cooper; Audi AG for the A3 and TT coupe; Volkswagen AG for the Golf, Passat and Touareg; and PSA Peugeot Citroen for the Citroen C5.

With the September launch of the LS 460, Toyota and Aisin AW collaborated on the industry’s first 8-speed automatic.

The unit, which is a claimed 10% lighter and 30% more rigid than the 6-speed transmission developed for the LS 430 (predecessor of the LS 460), contributes to smoother acceleration and improved driveability, according to Toyota.

The new 8-speed automatic channels the 4.6L V-8’s 380 hp and 367 lb.-ft. (498 Nm) of torque.

Aisin AW, a subsidiary of Aisin Seiki Co. and an affiliated supplier of Toyota, sold its first CVT in 2003 for the Toyota Sienta wagon.

It now provides CVTs for at least five Toyota models: the Sienta, Vitz, Belta, Ractis and Corolla, all compact vehicles with engine displacements under 1.5L.

Resulting from the lineup expansion, Aisin AW expects to sell 230,000 CVTs in the fiscal year ending this March.