New Audi A4
An
aluminum suspension, a low Cd figure, two newly designed engines, multitronic
CVT (continuously variable transmission), and a very clear family resemblance
to its larger brethren distinguish Audi's new compact sedan. An Avant (station
wagon) version will follow soon.
Audi's 2001 A4.
In
contrast with the launch of its radically designed all-aluminum A2, Audi has
chosen to tread a more cautious, evolutionary path with the new A4 (BMW did
much the same with its rival 3-Series); however, compared to its predecessor,
the A4 has sharper styling and a rising shoulder line that give it a wedge shape.
The A4 made its public debut at October's Berlin Motor Show and goes on sale
in Germany in January 2001. "Clarity and precision" were the guiding
elements of its styling, with "a reduction in the number of chosen lines
and creative devices" being a "crucial technique" used by the
design team, according to Audi.
The car's dimensions include an overall length of 4547 mm (179 in), which is
69 mm (2.7 in) longer than the outgoing model. At 1766 mm (70 in), it is 33
mm (1.3 in) wider and, at 1428 mm (56 in), is 13 mm (0.5 in) higher than the
outgoing model. The interior has Audi's established wraparound effect. The general
layout of the dashboard looks familiar, but everything has been redesigned,
according to the company. A large central information screen is placed ahead
of the gear selector but is fairly low; as with the strategies of most manufacturers,
the high position of the air vents in the A4 has a major effect on ergonomics.
With a wheelbase stretched 33 mm (1.3 in), the new A4 has more interior space.
Rear-seat knee room, a point of criticism on the old model, is improved by 41
mm (1.6 in). Trunk space has also increased.
The car's body structure is 45% more rigid than that of the previous A4. Although
Audi now has two aluminum models, the A2 and A8, the company believes that weight
"can also be reduced effectively" using modern steel construction.
The A4 has a unitary steel structure with integrated aluminum components. The
percentage by weight of aluminum, magnesium, and plastics has risen significantly,
while the proportion of steel and iron has been reduced by about 7.5%. A significant
element in saving weight is the use of high- and ultra-high-strength sheet-metal
panels, which make up about 45% of the body shell weight. These panels are used
mainly at the front of the car to aid impact absorption.
Tailored blanks are used in the new car's floor area to contribute to efficient deformation. According to the company, large-format tailored blanks can be structured in such a way that high wall thicknesses are only used in areas subjected to particularly high loads. A reduction in weight and a rigid structure can thus be effectively combined. In all, 10 large tailored-blank components are used on the new A4.
Since the early 1980s when Audi produced the 100 sedan with a Cd of 0.30, the company has focused on aerodynamic efficiency, although it is not the overriding design element that it once was. However, the new A4 achieves a very creditable best (depending on model) Cd of 0.28, which is 0.02 better than its predecessor. Designers paid particular attention to underbody airflow and used a new wind tunnel at the company's Ingolstadt headquarters, which has a glass floor to help facilitate test work. The improvement in aerodynamic efficiency has led to a quieter interior, with noise levels down by some 3 dBA.
Engine changes for the latest A4 include a new 3.0-L V6 with five valves per cylinder producing 162 kW (220 hp). Peak torque is 300 N·m (221 lb·ft) at 3200 rpm. In front-wheel-drive and five-speed-gearbox form, this engine motivates the car from 0 to 100 km/h (0 to 62 mph) in 6.9 s.
Although the bore and cylinder angle of 90° is the same as that for the 2.8-L engine offered previously, the new engine is said to share only a few components with it. The 3.0-L aluminum-block engine features a balancer shaft, lighter pistons, continuous intake camshaft adjustment, exhaust camshaft adjustment, two-position variable-intake manifold, Bosch Motronic MW 7.1.1 with electronic throttle control, and compliance with EU IV emissions mandates.
The car will also be available with a new 2.0-L four-cylinder engine with five valves per cylinder and output of 96 kW (130 hp) and 195 N·m (144 lb·ft) at 3300 rpm. It has a two-piston variable-intake manifold and a balancer shaft. As before, the new car is also offered with Audi's long-established 1.8-L turbocharged unit producing 110 kW (150 hp). There are two TDIs in the range: a 2.5-L V6 producing 132 kW (180 hp) and 370 N·m (273 lb·ft) between 1500 and 2500 rpm mated to a choice of five- or six-speed gearboxes, and a 1.9-L four-cylinder with 96 kW (130 hp) and 285 N·m (210 lb·ft) available from only 1750 rpm. The latter uses high-pressure pump-injector fuel injection with injection pressure up to 205 MPa (29,700 psi).
The multitronic CVT (already described by AEI and sampled in an A6) with a torque capacity of 310 N·m (229 lb·ft) can cope with the new 3.0-L V6 engine. Unlike earlier CVTs, most of the performance parameters for an A4 fitted with the system are superior to those of an otherwise identical vehicle with five-speed manual transmission, according to Audi.
The interior of the new Audi A4 continues Audi's established wraparound effect for the instrument panel and doors.
Audi's weight-reducing campaign sees four-link front suspension in light alloy for the A4, saving about 8.5 kg (18.7 lb) and cutting unsprung weight. Front- and all-wheel-drive versions of the A4 have self-tracking trapezoidal-link rear suspension, which also uses light-alloy components. All A4 versions get an Electronic Stability Program as standard. Brake Assist, which increases brake pressure in an emergency, is also fitted. A head airbag system, which covers most of the side windows, is standard, and smart sensors provide front airbags with controlled activation.
Stuart Birch
Renault's Modus2 and Operandi
Renault has been using its design expertise to produce new-concept light commercial vehicles. Called Modus2 and Operandi, they are modular and compact and described as "hyper-urban vehicles (HUV)." Hybrid motive power is used. It is six years since Renault unveiled the first Modus, and now it is advancing that concept. The two vehicles are 3.6 m (11.8 ft) long, 1.63 m (5.3 ft) wide, and 1.75 m (5.7 ft) and 1.54 m (5.1 ft) high, respectively. Space has been rationalized to maximum effect, according to Renault.
The Renault Modus2 concept.
Modus2
has four seats and an engine compartment at the front. Operandi has a rear engine
to increase loading space by placing the cab as far forward as possible. The
passenger seat can be folded away under the dashboard.
Renault's Operandi light-van concept.
Stuart Birch
