Mercedes W168 A-Class 1997 – 2001
On the Frankfurt International Motor Show in September 1993 Mercedes-Benz unveiled the study of a future class of vehicles with front-wheel drive, almost ready for production.
The “Vision A 93” immediately caught the eye of the world demonstrating in an impressive way that the Mercedes-Benz Advanced Design Team were the first to succeed in solving the conflict between the aim of compact exterior dimensions, spaciousness and variability inside and still meeting the high levels of security of a standard Mercedes-Benz in one unique overall concept.
Measuring an astonishingly short 3.35 m a degree of generosity in spatial distribution and easy accessibility of the interior could be realised otherwise only achieved by the grand mid-range saloons. A high level of versatility is another characteristic of the “Vision A 93”: from the comfortable four-seater up to a mini-van with a loading capacity of 1.000 liters all imaginable demands of our customers could be fulfilled.
The base of this revolutionary concept of space was a new raised floor assembly which enabled, a convenient side-effect to a certain extent, a degree of crash security that has never been achieved by a compact car before. The “Vision A 93” is more than a mere study of design and technology.
It is the forerunner on a new way into a section of the market that had not been defined until then and a guiding star for the development of the future Mercedes-Benz A-Class.
After the particularly positive response of public and media the search for the convenient future production location was intensified. Negotiations were long and arduous but on December 14th 1993 the choice was made in favour of Rastatt as plant for the production of the new A-Class.
These third passenger car works of Mercedes-Benz, inaugurated in 1992, were therefore given preference to, before the alternative positions in France, Great Britain and the Republic of Czechia. While the evolution of the A-Class went on as planned, the print media and the public were constantly informed about the latest developments – a way of proceeding never seen before in the history of Mercedes-Benz and especially not as long in advance of the start of series production.
In August 1994, 60 German and foreign specialist journalists were able to test the one-and-a-half million-marks prototype and to convince themselves of the practical usage of the future A-Class in everyday-situations. Two years after the “Vision A 93” world premiere the inside concept of the A-Class was presented at the IAA in Frankfurt in September 1995 with the total length already 225 mm longer than planned.
The availability of space, already quite satisfying before, was increased once more especially in the boot, and the extensive versatility of the interior has been recognised admiringly. At the same time the “Forum fürs Neue Automobil”, a care program “forum for the new car” was started with the declared aim to provide the interested public with current information about everything concerning the A-Class.
Another announcement made at the IAA was the declaration to expand manufacturing from the Rastatt location and to build up for this purpose additional production capacity in Brazil.
Construction started half a year later after corresponding contracts had been signed in Brasilia on April 19th 1996. From the end of 1998 on 70,000 units per year are going to be produced by 1,500 employees for the South-American market.
On May 20th 1996 the A-Class entered again the stage of public interest when a PR- and communication-campaign was lanced throughout Germany and six other European countries with TV spots, and advertisements in the print media and the Internet. The reason for this early beginning was the understanding that interested people are occupied with the purchase of a car as early as 12 to 18 months in advance.
As the new A-Class is a creation within an entirely new category of vehicles and potential clients could not refer to any other previous model it was the more important to create a certain familiarity between the people and the future product.
Shortly before, the W 168, as the A-Class is called on the internal level of Mercedes-Benz, had proven in several different crash tests performed at the engineering centre in Sindelfingen that a compact car with only short deformation distances is able to comply absolutely with the high safety standards of Mercedes-Benz.
It has become possible through the revolutionary new sandwich structure of the bodywork built of two levels laying on top of one another. The upper part constitutes the passenger compartment whereas the drive-aggregate is located in front of and under the intermediate floor.
In case of a front collision the drive unit slides along an oblique splash wall under the passenger cell and therefore cannot be of any harm for the occupants. The A-Class does not only fulfil the future EU Guidelines on frontal collision, it also fulfils the strict American and EU requirements for side impact.
The first official information and photographs of the final production version were released to the press at the beginning of December 1996. The world premiere of the A-Class took place three months later at the Geneva Automobile Salon. This event marked another milestone in the Mercedes-Benz product offensive just two months after the presentation of the CLK in Detroit. In the new model range more than 20 technical innovations were realised which had previously not existed in this category of car.
Due to the unique sandwich principle the A-Class achieved middle class levels of interior space and safety. The innovative rear seats and the removable front passenger seat provide the variability of a mini-van and mean that the five-seater can be converted to a four, three, two or one-seater.
A total of 72 different seating combinations can be realised and the loading volume of the A-Class can be compared with that of large station wagons 390 liters with the rear seat installed and 1,740 liters when all passenger seats are removed. The flat floor, the large rear door and the low height of the floor facilitate the loading of the luggage space.
The stable floor pan made up of a combination of straight longitudinal and lateral members is an integral component of the innovative safety concept.
At the front end of the longitudinal members there is a novel front module made of aluminium with a crash box at each side. These are screwed to the longitudinal members and can be replaced after an accident quickly and relatively cheaply. The front wings are made of plastic, for the first time Mercedes-Benz.
After a slight collision they regain their original shape; no repair or paintwork is necessary. In order to save weight the rear door is also made of plastic.
The repair-friendly design of the A-Class does nor only reduce repair costs after an accident, it also means that the cost of fully comprehensive insurance is lower. With respect to passive safety the new model range almost reaches the standards set by the E-Class.
This is due not only to the unique sandwich principle, but also to the standard restraint systems which were specially adapted to the concept of the A-Class with its short deformation distances. They comprise: full-size airbags for driver and front passenger, automatic seat belts with tensioners on the front seats and outer rear seats and seat belt tension limiters on the front seats.
As with the A-Class the engine and gearbox are fundamentalcomponents of the structure and safety concept, their design was particularly challenging.
Not only the engines’ intended cubic capacity, but also their planned dimensions meant that existing engines could not be used. Thus a completely new generation of 4-cylinder engines with aluminium alloy blocks was designed: two petrol engines, M 166 series, and two turbodiesels, OM 668 series. All four engines are more than 25 % lighter than other 4-cylinder engines with similar cubic capacity.
The engines are installed at an angle immediately under the pedal-floor. The upper side of the engine facing the passenger compartment is designed as a sliding surface so that the engine-gearbox combination can slide along and under the floor of the car in the case of a crash.
The petrol engines were available for the launch of the A-Class and develop 82 and 102 hp from 1.4 and 1.6 liters respectively. The introduction of the Diesel engines, with 60 and 90 hp, was planned for spring and autumn 1998. Both engines have 1.7 liter cubic capacity, four valves per cylinder, turbo-charging and electronically controlled direct fuel injection by the common rail method.
The 60 hp engine with optimised fuel consumption has its fuel volume limited, the turbocharger is specially adapted and there is no intercooler. To differentiate the two models the one with the weaker engine is named the A 160 CDI.
When these two Diesels were presented at Geneva, at first known as the A 160 Turbodiesel and. A 170 Turbodiesel (the CDI suffix came in November 1997), it was a world premiere for the common rail technology, which had been developed together with the Bosch company.
Whereas conventional systems create the pressure for each phase of injection anew, CDI engines work with a common rail, in which pressure is stored and released through magnetic valves to the injection nozzles.
The high injection pressure of up to 1,350 bar, which is already available from low engine revolutions, and the variable control of the injection process mean that the fuel/air mixture is much more effective resulting in low fuel consumption and pollutant emissions. However, this advanced Diesel engine technology first went on the market in the C-Class.
The first C 220 CDI cars were delivered in December 1997 after being presented at the Frankfurt Motor Show two months earlier. The new “Active Service System” ASSYST, which continuously analyses engine oil quality, means that service intervals for the A-Class engines are as long as they need to be according to actual operating conditions.
The result is that intervals can be as long as 40,000 km. These innovative 4-cylinder engines are produced at the Untertürkheim plant, where car engines have been made since 1904.
Not only the engines, but also the A-Class gearboxes are new developments, their shape is also adapted to the safety concept. The standard 5-speed manual gearbox weighs only 32 kg and is thus the lightest gearbox in its torque class. The 5-speed electronically controlled automatic transmission which became available as an option from fall 1998 is also one of the technical milestones of the new model.
With a length of 315 mm and a weight of 68 kg it is the shortest and lightest 5-speed automatic gearbox in the world. A cheaper alternative to automatic transmission is an automatic clutch, used for the first time in the A-Class.
When the driver takes his foot from the accelerator pedal and moves the gear lever, the system “realises” that he wants to change gear and operates the clutch by means of an electrical motor. The running gear of the A-Class is a completely new development; existing designs could not be taken over because of shortage of space. A modified McPherson system is used at the front, with coil springs, gas shock absorbers and torsion bar stabilisers.
The axle components, the rack and pinion steering gear and the engine-gearbox unit are mounted on an integral subframe, which is welded to the bodywork at eight points. A trailing arm axle is used at the rear, with coil springs, gas shock absorbers and torsion bar stabilisers.
This design of axle can be fitted under the floor pan without affecting loading space inside the car. The springs and dampers are positioned just inside and in front of the wheel centre.
The standard power assisted steering works with an electronically controlled pump with variable output. The tire-sealing kit, TIREFIT, is standard equipment on the German market instead of a spare wheel. If there is a puncture, this kit can be used to repair the tire for the drive to a garage. The kit includes an electric pump that can be plugged into the cigarette lighter. If desired, a full-size spare wheel can be supplied at no extra cost.
The concept of differing styling and equipment lines was also realised in the A-Class. Three versions are on offer: “Classic”, “Elegance” and “Avantgarde”, all with extensive standard equipment. Compared with the basic version “Classic”, the “Elegance” version includes a number of additional features which are visible both inside and outside the car.
Some of these features are: light alloy wheels, radiator grill and door mirrors painted to match the bodywork and chrome trim on the door handles. The “Avantgarde” line places the emphasis on technical features including light alloy wheels with low profile tires, silver painted radiator grill, monochrome rear light clusters etc.
The new A-Class went on sale on 5 May 1997, prices had been announced on 30 April. Production for the rest of 1997 was sold out quickly and potential customers soon had to accept waiting lists and long delivery times. In September 1997, four years after the presentation of the study “Vision A 93”, the final production version of the A-Class in its three styling lines was presented for the first time at the Frankfurt Motor Show.
In the same month, series production of the petrol-engined models A 140 and A 160 began in Rastatt. The body work of the A-Class consists of 290 single sheet metal parts welded together at 3.700 points.
It is subsequently painted in a unique process combining high environmental compatibility, efficiency and quality. This new fully automatic process, developed together with BASF and Dürr Systems, is an integrated painting concept with no need for a filler layer or body cavity treatment. From 18 October 1997 the A-Class was on sale and it seemed that the development work on this model had come to a successful conclusion. However, soon afterwards the unexpected happened.
The A-Class turned over during an extreme driving manoeuvre on a test drive in Sweden on 21 October causing world-wide publicity and threatening to cause lasting damage to the image of the new product and to the reputation of Mercedes-Benz itself. The Swedish so-called “elk test “, the extreme version of which is carried out at high speed with the car fully loaded, was soon being talked about everywhere.
An international press conference in Stuttgart on 29 October did nothing to improve matters. On the contrary, it led to further attacks, after journalists all over Europe had carried out their own more or less professional tests and had come to widely differing conclusions.
An expertise was issued by TÜV Südwest (Institution for Technical Tests) stating that the A-Class had been tested on 26 October under standardised and reproducible conditions and had proved to be absolutely safe and the Board of Daimler-Benz announced that the car would be fitted with the driving dynamics system, ESP, as standard equipment – yet the situation did not improve.
Then on 5 November the ADAC (German Automobile Club) came to the conclusion, after extensive testing, that the A-Class behaved just like other cars of its category in such tests.
At the same time car development engineers and technicians were feverishly attempting to find a form of suspension that would give the A-Class better results than the competition, even under such extreme and unreal test conditions.
The discussion, which had by now become quite heated, came back to earth on 11 November when Jürgen E. Schrempp, Chairman of the Board of Management of Daimler-Benz AG, presented the solution.
Testing and development teams had optimised suspension and running gear and found a solution which optimised the behaviour of the car under extreme situations. This know-how now had to be transferred into production as soon as possible; the modifications included new stabilisers, a new tuning of springs and dampers on the axles, a lowering of the body and the use of wider tires.
In order to go one step further and to give the A-Class a competitive advantage in the active safety department, the car was also fitted with ESP as standard equipment.
ASR, the anti-slip control system, and BAS, the “Brake Assist”, round off the standard equipment of the modified version. With this running gear and safety concept the A-Class now masters extreme driving situations that no other car of this category can cope with: on snow, ice or a wet surface. Preparation time of 12 weeks were necessary to put this concept into production. For this period production of the A-Class had to be interrupted.
Approximately 2,600 cars that had been delivered to customers were modified in specially set up service centres. The customers affected were able to hand over their A-Class and had the use of another Mercedes model until the modifications were carried out. On 10 and 12 November the A-Class received two coveted awards.
The first was the “Grand Austrian Automobile Prize” which Jürgen Hubbert of the Daimler-Benz Board of Management received from the Austrian Federal Chancellor Viktor Klima. The second was the “Golden Steering Wheel” awarded in Berlin by the newspaper “Bild am Sonntag”. In both cases the juries had come to their decisions before the accident in Sweden.
Not one of the jurors who decided on the Austrian prize had withdrawn his vote after hearing about the “elk test”. Daimler-Benz agreed with the “Golden Steering Wheel” jury to have an A-Class car equipped with ESP tested by a special expert member of this jury.
Rally driver Rauno Aaltonen performed the “elk test” and normed slalom tests 38 times at different speeds, but always over the required 60 kph and with different loads. On all tests the car proved to be well-behaved, safe and easily controlled.
The effect of ESP was impressive. Even when Aaltonen deliberately tried to provoke difficult driving situations, they were prevented by the electronics. Any last doubts were dispelled when an A-Class car with the modified running gear and ESP passed the “elk test” in Barcelona on 8 December with flying colours.
Not only German and Swedish journalists were at the wheel, but also the Formula 1 world champion Niki Lauda. The testers all agreed that the modified A-Class easily passed the “elk test”, also at high speeds, and confirmed that the new compact Mercedes had safe, agile and comfortable handling.
On 9 February 1998 the first modified versions were produced at the Rastatt plant. From 26 February all sales outlets in Europe could be supplied. At the Turin Motor Show in April 1998 Daimler-Benz presented a study vehicle which highlighted the versatility of the A-Class concept.
The “Turin” magma red show car emphasized in particular the sporty and dynamic appeal of the sub-compact multi-purpose car through special features introduced into the design of the interior and exterior. Discreet modifications were made to the styling of the front apron, side skirts and rear apron which, combined with five-spoke, 18-inch light alloy wheels designed specifically for the show car, helped to promote its sporting pretensions.
The design study was equipped with 225/35 ZR 18 low profile tires at both the front and rear. The commencement of deliveries of the A 170 CDI in July 1998 heralded the beginning of the Diesel era for the A-Class model range.
Three months later the A 160 CDI was launched, having already been on sale since June. In Germany, the A 160 CDI is only available in the Classic design and equipment line, featuring 5-speed manual transmission and 155/70 R 15 tire format.
However, elsewhere in Europe all other lines and an automatic transmission variant are also available and the A 160 CDI drives like its higher-performance brother using 195/50 R 15 format tires. In November 1998, the Wuppertal-based environmental institute “Öko-Trend” awarded the A 160 CDI the title of “Germany’s most environment-friendly car” paying tribute to “excellent all-round environment-friendly properties”.
For the first time a sub-compact vehicle, rather than a small car, has been credited with this coveted award which was the result of an investigation involving a total of over 1,000 passenger car models. In addition to the low fuel consumption, low exhaust emissions and noise level of the A 160 CDI, the environment-friendly production of the A-Class was also a decisive factor in its dominance over its competitors in being selected for the award.
Several days after receiving this award the A-Class was again the talk of the town. As part of the “Stars & Cars” motorsport event on November 14, which takes place every year at the Untertürkheim plant after the end of the motor racing season, Formula 1 World Champion Mika Hakkinen and his team mate David Coulthard were presented with company cars in a different class.
The A 190 Twin close-to-series study is fitted with twin 1.9-liter engines which generate a total of 184 kW (250 hp) and ensure an extremely sporty level of performance. The A 190 Twin takes the driver from 0 to 100 kph in 5.7 seconds and has a top speed of 230 kph.
This special edition car was constructed mainly form the components used in the series production model, demonstrating once again the versatility of the A-Class concept. Whilst one of the engines is front-mounted in the usual position under the hood, the second unit is located under the floor of the trunk and drives the rear axle.
Drive supplied by two engines would not be possible without the automatic clutch, which is also available as an option in the A-Class models in the sales range.
It ensures that both units are driven in tandem and that the clutch is activated on both engines simultaneously. The rear mounted engine can be easily deactivated at the touch of a button to create “mono mode”, whereby drive is supplied to the front axle only. The high-performance suspension and modified braking system take into account the superior power of the special edition car.
The A 190 Twin is fitted with 18-inch wheels and 225/35 R 18 tires.
The highly efficient brakes used on the E 55 AMG are mounted on the front axle and the rear axle of the sporty A-Class is also fitted with disk brakes. The bodywork, finished with gleaming silver paintwork, emphasizes the car’s dynamic characteristics.
The front spoiler, featuring a large cooling air inlet, has been mounted very low down which creates space for the rear mounted engine radiator and ensures power take-off from the front axle.
The front and rear wings are set a discreet 10 millimeters further out in order to create enough space for the 18-inch wide base tires. The wider side skirts and the broader and lower rear apron set the seal on the car’s sporty appearance.
