Suzuki's Wagon-R Plus is based on the company's Wagon-R light vehicle design, widened and powered by a bigger engine. Wagon-R Plus' engine is Suzuki's K-series 1.0-L inline four-cylinder unit. Opel's recently launched Agila is another Wagon-R derivative. Agila shares the basic structure with the Wagon-R Plus. Opel offers a choice of two Euro IV-compliant ECOTEC DOHC engines for the Agila: the 1.0-L inline three-cylinder and the 1.2-L inline four-cylinder. The Agila is built in a new factory in Gliwice, Poland. The Suzuki Swift is another small car derived from a kei car design. Swift is powered by a new light alloy 1.3-L engine. Mitsubishi's Pistachio is a widened Minica light car. Pistachio is powered by a new 1.1-L GDI engine fitted with an automatic stop-and-go device to conserve fuel.

K vehicle makers over the years have been exporting their minis. Honda's first serious entry in the U.S. market was the diminutive N600, a version of the N360 (yes, all of 360-cm3 displacement) with heftier bumpers. Suzuki, Daihatsu, and Subaru have been exporting their passenger and commercial minis to Europe and developing countries, again most of them powered by larger-displacement engines. Suzuki's Maruti joint venture in India produces its Alto K-based car, which is currently the most successful model in the country's growing market.

The astute Osamu Suzuki, President of the Hamamatsu-based mini and compact vehicle and motorcycle manufacturer, took K-segment competitors by surprise with the introduction of the tall, one-and-half-box Wagon-R six years ago. Over 1 million vehicles were sold in its first-generation form. The Wagon-R boom caused a flurry of activities among the competitors in Japan, who emulated the tall vehicle formula, as did two Korean companies, Hyundai and Daewoo (Daewoo's Matiz is based on a Suzuki-designed platform). A widened version called Wagon-R Wide was added, the suffix Wide replaced with "Plus." It was exported to 54 countries around the world, mainly European countries including Germany, the UK, France, and the Netherlands. Suzuki reports that more than 120,000 units of the first-generation Wide/Plus were shipped.

General Motors took a keen interest in the Wagon-R, seeing the strong marketability of Mr. Suzuki's "honey-I-shrunk-a-Suburban" mini in Europe and the Asia-Pacific region. It promptly began a joint development program with Suzuki on the second-generation Wagon-R. Suzuki launched its version of the collaborative project, the second-generation Wagon-R Plus, last summer. GM's Opel has recently introduced its Agila in Europe. GM's Asia-Pacific model, shown at the 1999 Tokyo Motor Show as the YGM, should follow.

The new-dimension K has been given an extra 100 mm (4 in) in overall length and 80 mm (3 in) in width. The new Wagon-R Plus has further enlarged the envelope, now exceeding the K car's dimensional limit. It is 3510 mm (138 in) long, 1620 mm (63 in) wide, and 1660 mm (65 in) tall, while sharing its 2360-mm (93-in) wheelbase with the mini. It now occupies about the same road space as a typical European B segment car but stands taller. The Plus is a five-door vehicle with versatile seating and luggage arrangement and is available in front- and all-wheel-drive configurations.

The Wagon-R Plus is powered by two versions of the aluminum K10A DOHC, 16-valve, fuel-injection, inline four-cylinder engine, displacing 996 cm3. Both naturally aspirated and turbo versions employ a VVT-i continuously variable intake-valve-timing system, which alters the timing by 60° for the NA unit and 30° for the turbo. The former is rated at 51 kW (68 hp) at 7000 rpm and 95 N•m (70 lb•ft) at 4500 rpm, while the latter puts out 74 kW (99 hp) and 122 N•m (90 lb•ft) at 3000 rpm.

Japan, like the U.S., is a country where buyers predominantly choose automatic transmissions for their cars, and Suzuki offers just that—an electronically controlled, four-speed automatic produced by JATCO TransTechnology. The steering-column-mounted selector lever allows slide-through facility for the front-seat occupants. The Wagon-R Plus is available in front- and all-wheel-drive configurations, the latter employing a RBC (rotary blade coupling) on-demand torque-split-and-transfer unit located mid-length of the propeller shaft. The difference in front and rear wheel revolutions turn the blade-rotor within the silicon-fluid-filled housing, generating pressure that compresses the multi-plate clutch, which transmits driving torque to slower-turning wheels. The RBC's operating pressure is relatively low, allowing the use of a lightweight aluminum housing to reduce mass.

The Plus shares the Wagon-R's front Mac-Pherson strut and rear tubular beam axle located by "isolated trailing links" and a lateral rod. The all-wheel-drive's live rear axle is similarly supported. The electronically controlled, vehicle-speed-sensing, electrically assisted rack-and-pinion steering mechanism acts on the steering shaft via a magnetic clutch and worm-and-wheel-gear assembly. The brake system comprises front ventilated disc and rear drum brakes, ABS with electronic brake distribution (EBD), and vacuum-actuated brake assist.

The Opel Agila is more of a twin to the Wagon-R Plus than a distant German cousin. While the two vehicles share a body that is distinctly Wagon-R, the Agila's face is more Opel than Suzuki, the adaptation cleverly accomplished by a design team headed by Hideo Kodama, a veteran Japanese director in charge of Opel's small car design.

The Agila's engines are from the Opel Corsa B-segment car. Two engine types are offered: the ECOTEC DOHC, 12-valve, fuel-injection, 1.0-L inline three-cylinder unit and ECOTEC DOHC, 16-valve, 1.2-L inline four. The former produces 43 kW (58 hp) at 5600 rpm and 85 N•m (63 lb•ft) at 3800 rpm and the latter 55 kW (74 hp) at 5600 rpm and 110 N•m (81 lb•ft) at 4000 rpm. Either engine is mated to a five-speed manual transmission, the natural choice of European small car buyers. The chassis is similar to the Suzuki model's, with electric power steering and ABS as standard equipment, the latter provided by Bosch. The Agila is built in Opel's newest plant in Gilwice, Poland (Suzuki's European manufacturing base is in nearby Hungary).

Mr. Suzuki's next "I-grew-my-mini-to-a-small-car" project is the Swift, derived from the kei hatchback, with its five-door body widened and 0.66-L engine replaced by a new 1.3-L inline four-cylinder unit. The car shares its basic platform with the Wagon-R Plus, with the same 2360-mm (93-in) wheelbase. Overall length and height are 3615 mm (142 in) and 1540 mm (60 in), respectively, and curb weight ranges between 920 and 960 kg (2028 and 2116 lb).

The Swift's engine is a new aluminum, DOHC, 16-valve, naturally aspirated, fuel-injected inline four-cylinder unit designated M13A. It obtains a total displacement of 1328 cm3 with over-square internal dimensions of 78.0-mm (3.07-in) bore and 69.5-mm (2.77-in) stroke. The cylinder block is aluminum into which semi-wet cast iron liners are pressed, as consistent with the Suzuki aluminum block construction practice. The cylinder bore is machined with a dummy head bolted on. The block is a deep-skirt design, with two additional bolts securing each of three center bearing caps. The forged steel crankshaft is fully balanced with eight weights. Dual overhead camshafts are driven by a single-stage silent chain of 8.0-mm (0.3-in) pitch, and in turn act on four valves per cylinder via bucket-type tappets, with clearance adjustment achieved by a shim inserted atop the tappet. The intake camshaft is fitted with a vane-type VVT-i continuously variable timing device, which alters timing within a range of 60°. The M13A engine is rated at 65 kW (87 hp) at 6000 rpm and 118 N•m (87 lb•ft) at 3400 rpm.

Again, the Swift is offered in Japan with an electronically controlled, four-speed automatic transmission only. The type A22M automatic is provided by Aisin, and used in both front- and all-wheel-drive versions. The AWD system uses viscous coupling integrated with the rear final drive unit.

Mitsubishi came up with a scheme of making a "three-liter car" out of a Minica mini car (i.e., a car achieving 3 L/100 km consumption on the Japanese urban 10/15 test cycle). As such, the Minica's K-size three-door body is pretty much left alone, with heftier bumpers lengthening it to 3440 mm (135 in); however, overall width remains at 1475 mm (58 in). The car, curiously named Pistachio, is powered by a gasoline direct injection (GDI) version of the 4A-series, DOHC, 16-valve inline four-cylinder engine, displacing 1.1 L. The Pistachio is offered only with a manual five-speed transmission, a rare concession aimed at optimizing fuel economy. The powertrain incorporates Mitsubishi's GDI-ASG, the suffix standing for "automatic stop and go," exploiting the GDI's ready start-ability, which fires up in only one-sixth to one-ninth the time of a conventional engine. The alternator is employed to regenerate electric energy on deceleration, replenishing the battery to compensate for the ASG's consumption.

Measures to conserve energy include electric power steering, lightweight stainless exhaust manifold, lightweight aluminum wheels, aluminum hood, thin-gauge glass, and an aluminum seatback. The Pistachio is more of a limited-scale experiment, with a production run of 50 units earmarked to environmental resource-conscious government and municipal agencies.

Jack Yamaguchi

AEI July 2000