Fiat Multipla: the car of tomorrow

We have changed our way of life and thus our way of perceiving the car. Until recently it was a status symbol: an object of desire we could fall in love with for its style, the aggressive or sophisticated image it could give us - or its high-tech content. Nowadays, it is a tool for work and pleasure from which we demand maximum practicality day in, day out.

We therefore came up with the idea of building an uncompromisingly practical car for everyday use. The result was the Fiat Multipla.

Six comfortable seats and a big luggage compartment in less than four metres of length. A strong personality, something refreshingly new within the current car scenario. Uncommon flexibility and versatility: these are the strong points of a model that offers a new driving experience by inventing the future. It is the forerunner of a brand new car category, characterised by extreme freedom in all senses: psychological freedom in its use of physical space - and freedom from preconceptions and the past.

The Fiat Multipla is a car for people who travel with friends and need six seats and a station wagon-sized luggage compartment. It is the car for leisure use that can adapt its number of seats to the number of passengers it carries (three, four, five or six) and use all the remaining space to carry luggage. It is the car for three people who wish to use the free part of the completely flat floor to carry long, bulky items. Its compact size and great visibility in all conditions make it the ideal car for everyday journeys through town traffic.

So many cars in one package. The Fiat Multipla is able to change to meet needs as and when they arise by changing its form (only for as long as required) to that of a station wagon, an MPV, a saloon, or a van. It therefore 'multiplies' (hence the name) possibilities of expression and movement while allowing free and inventive use of its interior space.

The conventional MPV market has expanded greatly during the last seven years (the European share rose from 0.5% in 1990 to 2.6% in 1997) but lacked a compact segment of cars able to offer the same basic characteristics as their bigger siblings, but with smaller dimensions and lower prices.

The Fiat Multipla abandoned the tried-and-tested architecture typical of single box and MPV (Multi Purpose Vehicles), i.e. two pairs of seats arranged over three rows, in favour of six individual seats of equal size, comfort and dignity arranged over two rows. It therefore succeeds in confining its length within four metres (it is 399 cm long, 4 cm shorter than the Fiat Bravo) while offering a roomy luggage compartment (from 430 to 1300 litres, according to rear seat position).

The floor is free of any intrusion. The floorpan lacks the usual step under the rear seat and is flat and high so that the extra components required by minimum environmental impact engines can be stowed underneath.

The two conventional versions equipped with a petrol engine (1.6 Torque 16v) and a turbodiesel engine (1.9 JTD) are joined by two ultra-clean Fiat Multipla versions, the methane-driven 'blupower' version and the 'bipower' version with a dual methane and petrol fuel system. These four vehicles will be joined in the future by a Fiat Multipla with hybrid power unit: electric and petrol.

Two specifications are available for each version (SX and ELX), both with a wealth of content and an impressive thirteen available colours including three pastel and ten metallic. A huge range of options and accessories allows you to bring some personal flair to your Fiat Multipla. But there is more. The new model also comes with a wide range of services which are customised for each market and designed to ensure peace of mind from all viewpoints: financial, service and safety. All these characteristics make the Fiat Multipla great value for money.

The new model is also innovative in terms of its manufacturing process. Its steel section space frame structure meets two different needs: maximum productive flexibility (essential in an expanding sector) and low fixed investments.

The Fiat Multipla is built at Mirafiori (Turin). Petrol engines are produced at Mirafiori Meccanica and diesels in Pratola Serra (Avellino). The low environmental impact versions are produced in Arese (Milan). Planned production when fully operative is 60,000 units per year. The new model is due to go on sale from November in Italy and from the beginning of 1999 in other European markets.

RESPECT FOR THE ENVIRONMENT:
Fiat has been engaged for years in the development of products and production processes that are kinder to the environment. This commitment has enabled us to achieve outstanding results in different fields: emission control, lower engine noise output, use of recyclable and recycled materials and the control of substances used and produced during construction. Like all the most recent Group models, the Fiat Multipla is built using harmless, recyclable materials. Some of its engines also run on intrinsically clean fuels such as methane and all use advanced, reliable emission control devices.

The catalytic converter on the 1.6 petrol engine is three-way and fitted with a Lambda probe. The probe monitors the amount of oxygen present in all exhaust gases moment by moment. The control unit uses input data from the probe to correct the amount of fuel injected in order to attain a stoichiometric mixture, i.e. containing exactly the right amount of air to burn all the fuel. The catalytic converter is therefore able to drastically reduce levels of all polluting compounds.

The 1.9 JTD power unit is fitted with an oxidising catalytic converter that uses excess air present in exhaust emissions to burn carbon monoxide and unburnt hydrocarbons. It also eliminates virtually all particulate, i.e. carbon and condensed hydrocarbon particles responsible for black smoke. This engine is also fitted with exhaust gas re-circulation (EGR), an electronically controlled system that recycles a percentage of exhaust gases to remove most of the nitrogen oxides.

Methane versions of the Fiat Multipla are fitted with catalytic converters designed specially for this type of fuel. Unburnt methane leaving the combustion chamber burns at a much higher temperature than the hydrocarbons produced by petrol. The catalytic converter temperature must therefore be much higher. To achieve this result, the new model is fitted with an exhaust pipe that brings the catalytic converter closer to the engine exhaust manifold. To promote chemical reactions, the catalytic converter also uses higher than normal levels of noble metals.

CONSTRUCTION:


The Mirafiori plant (Turin) was chosen to produce the Fiat Multipla. Petrol engines come from Mirafiori Meccanica and turbodiesel engines come from Pratola Serra (a few kilometres from Avellino). Low environmental impact versions are outfitted at the Arese Centre, close to Milan.

Mirafiori:

This Turinese plant was built in 1939 and celebrated production of its twenty-five-millionth vehicle in June. It covers an overall area of almost one million square metres. It works along integrated factory lines, i.e. for many parts it employs just-in-time principles whereby the line is supplied continuously without build-up of material. Components arrive at the point where they are used and only in the necessary quantity. The production cycle includes no slack: cars are put together and produced in an unchanging sequence.

Like all new models, various examples of the Fiat Multipla were produced in a pilot plant before going into production. The new car is so original that equipment, development and testing took engineers more than 35,000 hours.

The Space Frame, the model's special chassis, is prepared in the Panel Shop by assembling the various sub units. All these merge back into the main line where the sections making up the frame and the panels producing the car floorpan are added to the front frame. These operations are carried out on numerous high-tech welding stations. A Fiat Multipla body includes a total of 4500 weld spots. The high number of joints requires great care, particularly at the 'nodes', i.e. the body points subject to greatest stress. At the end of the cycle, a sophisticated electronic machine checks body geometry and measures hundreds of dimensions using two computer-guided probes.

The body then moves on to the Paint Shop, where the line has been adapted to the dimensions of the Fiat Multipla. This highly-automated process ensures final product quality. The panelled bodies firstly undergo pre-treatment to make the paint stick to the panel more effectively. This is followed by cataphoresis, an immersion process during which a protective paint layer is deposited on all interior and exterior surfaces. A second layer is applied automatically and then enamel is sprayed on by electrostatic robots.

A specific line is devoted to Fiat Multipla assembly. The personnel working on the line has undergone 85,000 hours of training. The ergonomics of each work station have received great attention. Devices have been added to aid personnel with more tiring operations. For example: the car is supported by hooks that can turn it around its longitudinal axis so that underbody operations can be carried out in a more user-friendly position with excellent visibility. Other advantages include a device that mates engine and body with the great precision and powered devices for fitting the larger components. Like other complex parts (doors, engines, suspension systems, etc.), the facia is assembled and inspected on a separate line.

At the end of the line, overall function testing is carried out by automatic, electronically-controlled instruments able to ensure maximum quality and perfect compliance of all parameters with specified values. Operations carried out in this way include: toe-in adjustment, testing of electrical equipment and engine control units, testing of suspension and brakes, emission tests, leak testing and on-road performance simulation.

Pratola Serra

The Fiat Multipla's 1.9 JTD engine comes from the Pratola Serra plant (Avellino). Opened in 1994, this is one of the most advanced engine production plants in Europe. The production lines consist of highly automated work stations and sub-stations and are produced to ensure maximum flexibility. They are therefore able to machine and assemble parts, units, sub-units and complete engines of all types: petrol or diesel, four or five cylinder - and two, three or four valve.

The main machining operations carried out at Pratola Serra concern the five most important engine components, i.e. crankcase, crankshaft, connecting rod, cylinder head and camshaft.

Materials flow is fully automated and managed by a central computer. Storage is minimised and production is organised in accordance with just-in-time principles. Each day, the plant produces only the number of engines specifically required for production.

At the Pratola Serra plant, each stage of machining is noted on an electronic device that accompanies parts throughout the production cycle. The monitoring and test systems of various stations are connected to a central computer. The result is a top quality standard of production.

GEARBOX:
The Fiat Multipla is fitted with two types of gearbox: one for the 1.6 Torque engine and the other for the 1.9 JTD.

Both transmission are outstandingly quite and slick and also very easy to manoeuvre. On the Fiat Multipla this attribute is accentuated by ergonomic studies carried out on the gear lever.

The various controls are made out of state-of-the-art components and were bench-tested for one and a half years under extreme climatic conditions. They have undergone the same sort of treatment as experienced in the factory during assembly, i.e. each component undergoes pre-inspection that involves electronic measurement of all engineering parameters responsible for determining efficiency.

Specific care has been devoted to reducing noise levels. The gearbox has been fitted with an inertia mass that cancels out the most annoying vibrations.

FRONT SUSPENSION:
The front suspension system used by the Fiat Multipla offers excellent comfort and effective roadholding. The classic independent MacPherson layout has been refined to achieve the best possible balance between both characteristics.

The coil springs are variable rate to meet all load conditions effectively. Their position, offset in relation to the damper, ensures reduced rolling resistance. Low noise is ensured by the presence of a rubber ring located on lower and upper plates.

The bump stops are made out of cellasto, a material which acts more gradually to ensure a smoother response on bends. These prompt reactions are also aided by an anti-roll bar connected directly to the damper. Compared to the conventional configuration with a bar connected to the suspension arm, this new solution reduces component weight by about 1.5 kg.

Suspension assembly noise levels are further reduced by double-acting pressurised hydraulic dampers. The oil scraper ring has been eliminated and replaced with an integral Teflon band on the piston to reduce rolling resistance.

The wishbones are in forged steel (to reduce unsprung weight by 1 kg), and angled 5 degrees in the direction of motion in order to minimise car pitching during braking (anti-dive).

REAR SUSPENSION:
The Fiat Multipla rear suspension is based on a classic independent configuration with tie rods, and a sub-frame suspended flexibly from the body.

This solution also helps limit car pitching and ensures good stability and minimum oversteer under heavy braking. The reduced transverse and vertical dimensions of this suspension also make the luggage compartment load platform more spacious. A particularly important attribute for a car such as the Fiat Multipla because the flat floor ensures great versatility of use.

A series of major refinements has been integrated into this classic configuration. The track has been widened by lengthening the intermediate frame pipe. A sophisticated adjustment also ensures better performance by the rubber and metal flexible blocks that connect chassis to the body to achieve an excellent balance between handling, ease of driving and comfort.

The hydraulic, pressurised rear dampers are connected to the suspension arm by a rubber bush fitted with a low friction coefficient ring (Krilon), which reduces torsional and rolling loads to improve operation. Additional anti-friction bushes on rod guide and piston also minimise friction inside the damper to ensure more effective absorption of road roughness, however slight.

The rear axle, with converging wheels, makes the car more stable during overtaking by ensuring safety and ease of driving. Variable rate springs also allow excellent comfort under all load conditions.

BRAKES:
The Fiat Multipla braking system employs a double crossover circuit (each circuit works on one front wheel and the diagonally opposed rear wheel) to ensure balanced braking even in the case of failure. The system includes self-ventilated discs at the front and drums at the rear. All four brakes are big enough to ensure powerful, safe braking even in the toughest conditions (when fully laden, for example).

The floating front brake calipers are fitted with a system designed to eliminate knock and are equipped with a brake lining wear indicator. The rear drum brakes are fitted with self-centring linings and automatic adjustment.

The ergonomically adjusted pedal takes just the right amount of effort to press: not so much that it tires the driver but not so little that it prevents good brake modulation. Credit for this is also due to the brake servo (9 inches) and the pump (13/16") which ensure promptness of response.

A load proportioning valve also ensures braking effort is correctly distributed over front and rear axles under all possible weight and roll positions: when the car is driven with only the driver on board, when the car is fully laden, when the car is driven in a straight line and when the car is cornering.

ABS:
All versions of the Fiat Multipla may be fitted as an option with a Bosch 5.3 ABS system, the most advanced available today. It comes with four active sensors, four channels and an eight-valve hydraulic control unit which contains an electronic brakeforce distributor (EBD).

Like conventional sensors, active sensors perform the task of measuring wheel speed, but they also process the signal themselves without needing to send it to the control unit. This means that the system is able to cut in more rapidly and can even detect speed signals close to zero (passive sensors do not record speeds lower than 4 km/h). Interference caused by electromagnetic fields is also lower.

The EBD distributes braking force over all four wheels in order to prevent the rear wheels locking and ensure full control of the car under all conditions. It also adapts system operation to wheel grip conditions and pad efficiency, while reducing the thrust required from the brake servo.

STEERING:
Light and easy to handle during parking manoeuvres and at low speed, the Fiat Multipla steering system is precise and safe when the car travels at higher speeds. It is fitted with a particularly quiet power steering system which comes as standard on all versions. The steering box is also fitted with bigger racks and links to ensure constant driving precision and reliability over time (elasticity is reduced).

The pump output variation law has been optimised for engine rpm level and ensures ease of operation and handling in all service conditions. This result is also aided by a low servo ratio (4.4 Nm/40 bar). During steering, the effort applied at the steering wheel from a standstill is just 0.4 kilograms.

The Fiat Multipla has a turning circle of just eleven metres.

ENGINES:
On many cars, engines determine the personality of versions within the range (economical, sporty, etc.). The approach is completely different on the Fiat Multipla. The engines were specially selected to adapt to this car's innovative brief: a car that is easy to drive, comfortable, dynamically safe, with respect for the environment and designed today for traffic conditions of tomorrow.

The choice offered by the five Fiat Multipla engine versions is not between different performance levels but between different fuel supply systems.

This is another breakthrough for the model: the Fiat Multipla is the first car to be created with petrol engines (1.6 16v), a diesel engine (1.9 JTD), a methane engine ('blupower'), a methane-petrol engine ('bipower'), and a petrol and electric engine (hybrid).

Like all Fiat engines, the Fiat Multipla power units ensure refinement, good performance and low fuel consumption. They also meet environmental protection specifications with plenty of room to spare. Noise levels are maintained below 74 dB and emissions levels are well below EU Stage II limits.

1.6 Torque 16v:
The Fiat Multipla petrol power unit is a 1.6 16v 1581 cc unit. It belongs to the family of 'torque' engines, which owe their name to their ability to deliver a well-rounded and smooth torque curve. The engine offers lively performance and a balanced, flexible and satisfying drive. Everything one would expect from an engine destined to satisfy the needs of a wide-ranging public which will use the vehicle equally on mixed routes and on the motorway.

The result is 103 bhp (76 kW) of maximum power obtained at 5750 rpm and 14.7 kgm (144 Nm) of maximum torque at 4000 rpm. Almost 85% of this pulling power can be called upon through a wide range of speeds, from 2300 to 5800 rpm. The performance figures are everything one would expect and they can be summarised as 170 km/h at top speed in fifth gear and acceleration from 0 to 100 km/h in 12.6 seconds. Fuel consumption measured according to ECE+EUDC standards are 8.6 l/100 km.

This engine is 'supersquare': its bore and stroke specifications are 86.4 and 67.4 mm. The cylinder head incorporates four valves per cylinder, with twin overhead camshafts controlled by a toothed belt. The tappets are hydraulic and allow automatic valve adjustment. The toothed belt tensioner is also automatic.

The multivalve design increases air flow and thus power and torque. This brings the benefit of more compact combustion chambers. For the same volume, the area exposed to gas is lower and therefore heat exchange with coolant is lower. This improvement is translated into lower fuel consumption for the customer.

The specific cylinder head cooling circuit also ensures system efficiency for greater power unit reliability and durability.

The intake and exhaust ports on the 1.6 16v were computer designed (CAD-CAE) using fluid dynamic simulation programmes to ensure effective mixing and load distribution between cylinders. The intake manifold also features long branches (400 mm) to improve power delivery at low and medium engine speeds.

The integrated ignition-injection system is a Weber-Marelli multi-point system with static ignition and miniaturised injectors. It is controlled by a new management unit with high capacity and processing speed, which ensures a smooth drive and precise emission control under all driving conditions. Selective knock control (cylinder per cylinder) ensures higher engine performance and total reliability even in the case of operating anomalies (e.g. use of fuel with a lower-than-specified octane number).

Other distinctive features of this power unit are pistons designed to reduce noise levels and cylinder liner treated with a plateau finish which insures better lubrication and lower engine oil consumption.

1.9 JTD:
The turbodiesel unit is the 1910 cc 1.9 JTD unit with Unijet direct injection system. Due to electronic control of pump and injectors, this type of common rail system is able to adjust the amount of fuel taken into the cylinders by using a very high injection pressure regardless of engine speed. It is also able to control very small quantities of diesel to carry out a pilot injection or pre-injection ahead of the main injection for smoother, less 'rough' combustion.

The result is a highly reliable engine capable of superior performance. Its fuel consumption is reduced by some 15% compared to power units with a pre-chamber. This power unit also ensures a high level of comfort characterised by no vibration and a level of noise until recently inconceivable for a diesel engine.

The variable geometry Garrett turbocharger alters vane angle to speed up or slow down gas speed to adjust turbine rotation speed and thus turbo pressure effectively. It exploits exhaust gas energy as effectively as possible to adapt to the various engine service conditions. When combined with an intercooler, it ensures the 1.9 JTD unit a high power output (105 bhp - 77 kW at 4000 rpm), excellent torque at low speeds (200 Nm equal to 20.4 kgm at 1500 rpm) and great driving flexibility.

When fitted with this engine, the Fiat Multipla reaches a top speed of 170 km/h, accelerates from 0 - 100 km/h in 12.4 seconds and pick-up in fourth from 60 to 100 km/h occurs in 9.7 seconds (14.9 seconds in fifth gear from 80 to 120 km/h). Fuel consumption measured according to the new ECE rule (urban route), plus EUDC (out-of-town route) is low: 6.4 l/100 km.

The 1.9 JTD design features four cylinders with two valves per cylinder, parallel and vertical, driven directly by a single overhead camshaft. The engine contains no pre-chambers because the entire combustion process occurs in the combustion chamber within the piston. The light alloy cylinder head features pistons with an 'omega-shaped' combustion chamber and screw-shaped intake port that swirls the air around for more effective combustion. The crankcase is in closed-deck type cast iron, i.e. with integral cylinder liners and intermediate cooling.

Another important feature of this power unit is a dual damped flywheel (DVA), which ensures a very smooth drive. Consisting of two masses, one mass is attached to the crankshaft and the other to the gearbox mainshaft, the system reduces vibration at low speeds and transmission noise to increase driving comfort.

METHANE POWER UNITS:
Why methane Fiat Auto was the first manufacturer to offer a dual fuel system vehicle produced in a factory and sold through the normal sales network: the Marea Bipower. Now it is the first manufacturer to launch two versions specifically designed to run on methane or compressed natural gas (CNG), as it is otherwise known. These are the Fiat Multipla 'bipower' and the Fiat Multipla 'blupower'.

Many reasons influenced our decision to produce two engines. Apart from being a widely available energy source (world reserves are higher than oil reserves), methane is a clean fuel and thus consistent with Fiat policies - we have been concerned with green issues for some years. Compared to petrol, methane does not generate benzene or particulates during combustion, and reduces carbon dioxide emissions by some 25% and emissions of uncombusted non-methane hydrocarbons by 95%. It is therefore able to satisfy the toughest limits in the world, i.e. the Californian standards governing ULEVs (Ultra Low Emission Vehicles).

The financial benefits are also undeniable. This market is therefore currently limited in volume and territorial coverage but is certainly due to expand. This growth will be accelerated by the arrival of the Fiat Multipla, a car destined to bring about a leap in quality within the sector.

Fiat Multipla 'bipower' and 'blupower' The Fiat Multipla is the first vehicle to offer two true methane versions at launch. The new model has not been simply adapted to work on methane as well as on petrol (as is the case with petrol vehicles transformed after sale) but has been designed and developed specifically to be fitted with methane supply systems.

The two versions do not just follow in the tradition of the Fiat Marea bipower but represent a natural development from that car. On the Fiat Multipla, the decision to use natural gas does not affect the space inside the car or its driving range. The flat, high vehicle floorpan means that the cylinders can be positioned beneath the floor, outside the passenger compartment.

The range offered by these two versions of the Fiat Multipla is also extensive: up to 500 kilometres for the 'bipower' (which offers the same range when run on petrol) and up to about 700 for the 'blupower'.

Natural gas is loaded at a pressure of 200 bars into 4 mm-thick steel cylinders. The Fiat Multipla 'bipower' is fitted with three (for a total of 164 litres) while the 'blupower' is fitted with four (216 litres). These considerable volumes are due to the properties of the fuel itself. Four litres of compressed methane are necessary to produce the same energy as a litre of petrol.

Fuel system. Methane flows from the cylinder through pipes to a reduction unit fitted in the engine bay, which reduces pressure from its original level of 200 bars to about 9 bars. The gas then flows into four injectors. The fuel system of both Fiat Multipla methane-driven 1.6 Torque 16v engines is innovative compared to the system used on converted cars currently available on the market. The power units are fitted with injectors specifically designed for this fuel. The 'bipower' engine comes with two separate fuel systems, which are managed by a single phased sequential multipoint control unit.

Specific features of the two versions. Compared to the petrol engine, the 'blupower' offers different timing and a higher compression ratio. These characteristics are unchanged in the 'bipower' power unit, which is designed to work on both fuels. The 'bipower' version normally runs on methane and the driver can choose to switch over to the petrol option at any time. In two cases, however, switching is automatic: for a few seconds the first time the car is started up after refilling to prevent damage to the petrol injectors caused by prolonged inactivity - and when the methane is about to run out.

Catalytic converters. Both Fiat Multipla methane versions are fitted with catalytic converters specially designed for this fuel. Methane which emerges from the combustion chamber unburnt burns at a higher temperature than hydrocarbons produced by petrol. The catalytic converter temperature must also therefore be higher. In order to achieve this result, the catalytic converter in the new model's exhaust system is very close to the engine exhaust manifold. Compared to petrol units, the methane version catalytic converter uses a higher quantity of noble metals to promote the appropriate chemical reactions.

Safety. The Fiat Multipla 'blupower' and 'bipower' fuel system is also much safer. Firstly, due to the intrinsic properties of non-toxic methane, its float rate is high (i.e. it disperses into the air very quickly) and it catches fire at twice the temperature of petrol and diesel vapours. The Fiat Multipla methane versions also incorporate a set of safety devices that minimise risk in the case of impact or failure.

- Two solenoids isolate the part of the pipes into which high pressure methane flows. One is located on the reduction unit, the other on the fitting of each individual cylinder. They are connected to the inertia switch and block methane flow in the event of impact. They are both shut-down when the car is not methane driven.

- A system limits methane flow when an excessive quantity of gas emerges due to an anomaly or piping failure. Located inside the cylinder, it also cuts in if the solenoid is broken due to impact.

- If the temperature increases for external reasons, a fuse pad totally eliminates the danger of excessive pressure rises by venting (in the form of a limited, controlled flow) the methane contained in the cylinder. The Fiat Multipla 'blupower' and 'bipower' both pass fire tests with flying colours: no flame increase was noted due to controlled methane release when a car was set alight with its cylinders full.

- Finally a check valve on each solenoid prevents methane flowing back to the filler cap.

The mechanical system of the new model was also designed specially for these engines. The suspension settings are different to that of petrol and diesel versions to ensure excellent roadholding and maximum comfort. The cylinders are also protected by a guard to prevent damage by gravel or other factors.

FIAT MULTIPLA HYBRID:
A reduction in environmental impact is one of the crucial factors considered when developing new models and Fiat Auto is working in several directions to this end. Apart from the Fiat Multipla 'blupower' and 'bipower', it now also offers a third alternative to conventional engines: a hybrid Fiat Multipla, which will go on sale at the end of 1999.

In hybrid cars, an internal combustion engine is connected mechanically or electrically to an electric engine, which can aid or replace the main engine under different service conditions. The electric engine is constantly powered by batteries and the batteries are powered by an electric generator if necessary.

On the hybrid Fiat Multipla, the internal combustion engine is petrol-driven (the 76 kW 1.6 16v Torque unit) and the electric motor is triple phase and asynchronous (30 kW). The batteries are metallic Nickel-hydride, with high energy density (70 Wh/kg, 19 kWh total). The generator consists of a high power alternator (15 kW) complete with current rectifier.

Power steering, brake servo and air conditioner are electrically powered. The electronic system that controls the drive components and the Inverter (i.e. the converter that transforms direct current delivered by the battery to triple phase alternating current taken up by the engine) are located in the console between the two front seats. The batteries are secured beneath the floorpan in a central position. The recharging lead socket is on the left rear side. The operating mode selector is on the facia and selection can be repeated on the instrument panel, which also features a battery charge status gauge.

The hybrid Fiat Multipla is a true multimode car due to its dual input Selespeed gearbox and automatic clutch, which connects the engines to the gearbox in different combinations. The car is indeed able to work in two modes: - hybrid: when both electric motor and petrol engine work simultaneously and both help propel the car forward; - electric: when the Fiat Multipla is propelled solely by the electric motor, with the internal combustion engine off and disconnected.

The decision to make the car work in hybrid or electric mode is taken by the driver, who can operate the selector on the facia at any time.

Let's take a closer look at the two operating modes:

Hybrid. Both engines act in parallel on the wheels. A sophisticated electronic system distributes the power delivered by individual engines in order to exploit the different characteristics of each to the full. Although the electric engine is less powerful, it delivers a high torque from take-off, while the internal combustion engine develops high power with reduced fuel consumption while running at an almost stationary speed. At start-up, therefore, the car is driven by the electric engine alone. The petrol engine then cuts in and drives the car at constant speed up to a maximum of 150 km/h. During pick-up and over-run (transient states), the petrol engine is assisted by the electric engine, which improves pick-up and saves energy during over-run and braking. During hybrid operation, the driver can call on four speeds plus reverse from the Selespeed gearbox.

Electric. This is the ideal mode when driving around town because it is noiseless with very low emissions (the Fiat Multipla is a ZEV, Zero Emission Vehicle). When this mode is selected, the car is driven by the electric engine alone because the internal combustion engine is off and disconnected. Top speed is 80 km/h and the Selespeed gearbox offers two speeds plus reverse. Range is 70 kilometres over an ECE cycle. The batteries may be recharged at any time from the normal electrical mains through the on-board battery charger.

When this is not possible and the batteries are nearly flat, electrical EA (Extended Autonomy) mode is implemented automatically. Under these conditions, both engines are operational but are used for different reasons. The car is driven by the electrical motor alone, while the internal combustion engine works at stationary speed to drive the battery recharging generator. This mode is turned off automatically as soon as the battery charge is high enough. When the hybrid Fiat Multipla works in this third mode, it may be considered an EZEV (Equivalent Zero Emission Vehicle). Exhaust emissions are the same as the overall emissions produced by an electrical vehicle (ZEV), even counting the electrical energy production process within a thermoelectric plant.

THE "SPACE FRAME":
The Fiat Multipla is also an innovative model in terms of its manufacture. It is not produced using a normal load-bearing body but using a structure known as a Space Frame. This means that the body panels are applied to a car skeleton made up of welded steel sections. This engineering choice offers important advantages:

High rigidity. The use of high-resistance and various thickness steel sections (which can now be produced using new technologies) makes it possible for each component to be made rigid enough without affecting overall vehicle weight. The car's level of torsional and flexural rigidity is therefore increased.

Excellent resistance to impact. Because the Fiat Multipla floorpan is made out of low, straight rails, the force of frontal impact is discharged downward and does not deform the passenger compartment cell. Overall, car safety is therefore increased. The Space Frame also makes it easier to differentiate between car structures more easily and add extra strength where it is needed.

More effective use of available space. The Fiat Multipla car is built around its passengers and their requirements. For this reason, the car's designers adopted a solution that prioritises passenger space: a flat floorpan. All bulky items are positioned beneath the car and the seats may therefore be positioned in the most user-friendly positions.

Appearance. This engineering solution gives the Fiat Multipla its highly original line. One of the sections making up the Space Frame is visible at the top of the car, where it becomes an unmistakable styling element.

Flexibility. The Space Frame allows greater design flexibility. Body changes can be achieved by adjusting only the affected area. This structure also makes it easier to produce derivative vehicles.

Lower industrialisation costs. Sections are machined in special machines known as rollers that bend the sections into the required shape. This technology is sophisticated but relatively low-cost. Because the frame is made up of all these elements, the number of pressed parts can be reduced. Fewer moulds means lower investments.

Environment. The Space Frame also offers environmental benefits because it reduces panel wastage.

Our decision to use a Space Frame for a standard production model meant a new engineering and design approach. The engineers had to do plenty of work on the welding of body 'nodes', which must ensure the greatest possible rigidity and resistance to wear. Great care was also taken to ensure that this system of joined-then-assembled sections guarantees the same tolerances as a conventional pressed part.

STYLING:
The Fiat Multipla body was created around six passengers sitting in two rows and their luggage. The shape takes into account their need for comfort and makes it possible to conduct normal social relationships within the group while also offering an intensely experienced relationship with the outside world plus maximum protection and safety. This approach foregrounds practicality by reconciling passenger needs and desires with technological possibilities.

Without, for that reason, shelving the idea of creating a line that is consciously different from usual, a line that is capable of communicating, in its aesthetic aspects too, that here we have a new way of conceiving the car. The Fiat Multipla is innovative in its contents and its styling states this without hesitation.

LINE:
The car is designed around two modules, a low, penetrating basic body with a high, generous roof panel superimposed on top. Both elements are strikingly separated by a sort of band (waistline) sloping towards the front part of the vehicle. This shape has the functional purpose of extending the passenger compartment upward to create more headroom and make the space below the waist more compact so that it covers only the amount strictly necessary.

It would, of course, have been possible to bring bonnet and windscreen into line by returning to the conventional one-box front end design, but the extra box would have served no purpose.

Seen from behind, the car's styling is highly personal and unconventional. Its shape does away with the more or less accentuated convex forms we are used to seeing on present-day cars. So even when three seats are lined up on the same row, for example, the heads of the people sitting on either side are far from the walls and no sense of constriction is felt. Exterior visibility is improved and the road is visible right round behind the vehicle (this result is aided by a good side view due to a very low waistline and windows that drop to half way down the car).

On rainy days, you can also open the door or window without water dropping from the roof onto the seats. When the car is parked for a long time in full sunlight, the almost vertical windows ensure a lower interior temperature than recorded for any other car.

Practicality and styling courage also come together in the decision to arrange the lights on different planes, which is partly responsible for the original appearance of the front end: three pairs of round headlights arranged at different heights. In fact they are better able to perform their task of lighting the road in this position: the foglights are placed low down in the bumpers; the dipped beams are further up in the upper part of the grille - and the main beams are even higher up in the convex band at the base of the windscreen where they are able to light the road further around the car, reduce light beam pitching and improve visibility on bends and winding roads.

The tail-lights are arranged to look like traffic lights within a heart-shaped cluster: brake light at the top, side light in the middle and rear foglight at the bottom. The turn signal is enclosed in the light cluster and takes the form of an arrow pointing to the outside of the vehicle.

The aim with the Fiat Multipla was to allow passengers to get in and out of the car in comfort without having to twist themselves into uncomfortable positions or strain their legs. This has been achieved by adopting a completely flat floorpan and locating the door side pillars as far forward as possible.

The door pillars feature an unusual geometry that follows the curved line of the structure profile, thrusting far forward at the top where the window is housed and then folding back and dropping at right angles. The glazed area is therefore unbroken by any pillar.

Almost as if to emphasise the way the structure is integrated with the boxes, both parallel sections that anchor the roof panel to the vehicle base body are visible and run along the length roof like two slightly protruding ribs. The structure therefore visually emphasises its function of protecting the passenger compartment, i.e. its role in ensuring occupant safety.

INTERIORS:
Inside the car, the same design philosophy led to careful space husbandry: clever elimination of wasted space with every opportunity exploited to the full.

In order to arrange two rows of three seats side by side (equally comfortable and generous in size), door bulk had to be minimised on the inside by removing all service elements: arm rests, opening lever, etc. The handle, for example, points upward and is evident through the clear glass when the car is locked. This solution is practical, simple and direct.

The seats can be moved, removed and adjusted at will for a great range of interior configuration possibilities. The Fiat Multipla environment promotes conviviality and conversation. It also offers a more or less generous load platform, according to current needs.

The instrument and control arrangement is absolutely innovative. By convention, the facia is a flat surface on which the various instruments and controls are assembled. The Fiat Multipla stylists redesigned the facia to be three dimensional. The angled surface looks like a working table on which the various controls, gauges and objects are arranged to make the most of the available depth.

Everything is arranged to be as rational as possible. The designers took into account the frequency with which each item is used, the most effective distance for easy reading and membership of similar or complementary functional sets.

The result is striking from a formal point of view and ensures easy and intuitive monitoring of the various instruments, which are all easy to recognise and read.

The instrument panel looks as though it has been placed on the facia. Situated slightly to the right of the steering wheel, it is angled towards the driver, who is able to consult easily without lowering his eyes, just as a computer operator throws an occasional swift glance at the screen. The panel's greater distance also ensures easier, faster reading.

Air exchange and ventilation take place through a climate control 'tower' that emerges from the facia surface. The most important controls and instruments are clustered on a central area.

The gear lever, the most important interface in the continual dialogue between driver and machine, is situated on a console alongside the steering wheel.

A host of compartments make the most of every corner of the car and provide room to stow everything away: compartments above and below the facia and compartments beneath the sun visors; soft pouches arranged behind the seat squabs and rigid pouches on each door; a box beneath the right front passenger seat plus radio and phone compartments.

Story by Fiat Edited by Maximum-Cars.com