The new Fiat 500 goes on sale in the UK with a choice of three powerplants, all of which are manufactured by Fiat Powertrain Technologies. With an annual output of some 2.8 million engines and 2.1 million transmissions, FPT is one of the most significant players in the worldwide powertrain sector.

The new Fiat 500 engine range comprises the latest, 75 bhp derivation of Fiat’s widely acclaimed, state-of-the-art 1.3 litre 16-valve MultiJet turbodiesel, and two refined and economical FIRE petrol engines – a 1.2 litre 8-valve, 69 bhp unit and a spirited 100 bhp version of the 1.4 litre 16-valve powerplant.

Not only are all three powerplants Euro 4-compliant, but they have also been designed to meet the even stricter Euro 5 emissions regulations due to come into force in 2009.

Both the 1.2 litre petrol engine and 1.3 litre turbodiesel are fitted with 5-speed manual gearboxes, whilst the 1.4 litre petrol unit is mated to a 6-speed manual transmission. Dualogic – a clutchless, 5-speed sequential manual shift with a selectable fully automatic mode – is offered as an optional transmission on both petrol-engined Fiat 500 models.

1.2 8v FIRE

• 1242 cc
• 4-cylinders, 8 valves
• Power: 69 bhp @ 5500 rpm
• Torque: 75 lb.ft @ 3000 rpm
• Top speed: 99 mph
• Acceleration 0-62 mph: 12.9 seconds
• Fuel consumption: in town: 44.1 mpg
• out of town: 65.7 mpg
• combined: 55.4 mpg
• CO₂: 119 g/km

This tried and tested unit is installed in the new Fiat 500 with a number of refinements to further improve fuel economy without affecting its lively performance.

The engine is fitted with a sophisticated, Marelli I.A.W. phased sequential multipoint injection and a drive-by-wire, electronic throttle control system. New, convergent / divergent intake ports and camshaft profiles optimise power and efficiency, and a new active knock sensor manages ignition advance effectively under all conditions.

Fluid dynamic optimisation has been achieved by a new, high-turbulence combustion chamber, and lighter componentry has also improved fuel consumption. In particular, a new glassfibre reinforced polymer intake manifold has been developed with U-shaped branches and a built-in plenum, while lightweight timing components and low-load valve springs reduce friction.

A new auxiliary drive circuit featuring built-in mountings in aluminium ‘squeeze’ castings and an automatic low torque tensioner has also been developed for improved reliability – a factor which has been further enhanced by mounting the coils together in a single block, the new coil type effecting a reduction in spark plug wear, better cold starting, and, through the adoption of very short high voltage cables, a significant reduction in the risk of disturbance to on-board instruments.

The quality of life on board has been improved through optimising the performance of both intake and exhaust systems, and the coupling ‘play’ between the crankshaft and crankcase. NVH has been further reduced through computerised selection of the main bearings, and a special engine installation system which minimises the transfer of engine vibrations to the body – a barycentric power unit mounting system consisting of two blocks plus a reaction rod that acts as a link. The new mounts are aligned along an axis that passes through the engine's centre of gravity to obtain reaction forces with zero offset.

Additionally, the catalytic converter is welded to the side of the exhaust manifold within the engine bay, allowing it to reach the necessary high working temperatures more rapidly, thus reducing emissions before the engine itself is at optimum running temperature.

1.4 16v FIRE

• 1368 cc
• 4-cylinders, 16 valves
• Power: 100 bhp @ 6000 rpm
• Torque: 97 lb.ft @ 4250 rpm
• Top speed:113 mph
• Acceleration 0-62 mph: 10.5 seconds
• Fuel consumption: in town: 34.4 mpg
• out of town: 54.3 mpg
• combined: 44.8 mpg
• CO₂: 149 g/km

With a bore of 72 mm and stroke of 84 mm, this new 100 bhp 1.4 16v FIRE unit marries a drive-by-wire, electronic throttle control system to new engine control unit management software.

An increase in compression ratio and the unit’s high torque values at low engine speeds, allied to the precision management of the engine control system succeeds in reducing fuel consumption whilst optimising performance – areas in which the new Fiat 500 is at the top of its class.

Volumetric efficiency has been optimised throughout the operating range courtesy of careful fluid dynamic development of the entire intake system and timing phasing. And the reduction of friction through the adoption of lighter timing components and low-load type valve springs further reduces fuel consumption.

In order to guarantee low emissions, a new injector type has been adopted to optimise the spray phase, thus reducing the quantity of fuel that adheres to the
intake manifold walls during cold starts and under throttle loading, which, in turn, reduces the quantity of hydrocarbons in the exhaust gases. As with 1.2 litre FIRE units, a catalytic converter is welded to the exhaust manifold within the engine bay, and the 1.4 litre engine is fully Euro 4 compliant.

Sharing the 1.2 litre engine's barycentric engine mounting system to minimise the transfer of vibrations to the body, the 1.4 16v FIRE unit also benefits from a number of further developments designed to minimise noise, vibration and harshness: an aluminium crankcase base with cast iron main bearing caps cast together; an aluminium oil sump connected directly to the base of the crankcase and gearbox to increase the torsional rigidity of the combined unit; a crankcase and flywheel system damper to minimise vibration; and an optimised piston skirt profile with a molybdenum bisulphate coating to minimise piston/liner clearances and thus reduce noise.

1.3 16v MultiJet Turbodiesel

• 1248 cc
• 4-cylinders, 16 valves
• Power: 75 bhp @ 4000 rpm
• Torque:  107 lb.ft @ 1500 rpm
• Top speed: 103 mph
• Acceleration 0-62 mph:  12.5 seconds
• Fuel consumption: in town:                  53.3 mpg
• out of town:     78.5 mpg
• combined:        67.3 mpg
• CO₂:                111 g/km

Weighing just 130 kg, the 1.3 litre 16v MultiJet – a 1248 cc, 4-cylinder in-line unit with a bore of 69.6 mm and a stroke of 82 mm – is the smallest and most advanced second generation Common Rail direct injection turbodiesel in the world. More than two million units have been built to date.

It features twin overhead camshafts, a chain driven timing system, hydraulic tappets, a cast iron crankcase with an aluminium base, a steel crankshaft and an aluminium cylinder head. The cylinder head is equipped with highly efficient directional intake ports to ensure an optimum fuel mix despite the small bore. The 1.3 MultiJet engine is boosted by a Borg-Warner fixed geometry turbocharger with wastegate and intercooler, and possesses an electronically controlled exhaust gas recirculation and cooling system.

The engine offers two highly innovative features: extremely compact dimensions (460 mm long, 500 mm wide and 650 mm high) that enable it to be installed in city cars, and the sophisticated MultiJet technology of second generation JTDs. The latter is the result of groundbreaking and ongoing development work at the Fiat Research Centre in Turin, itself responsible for the introduction of the world's first UniJet Common Rail engine in 1997.

Within a UniJet engine, a pilot injection raises temperature and pressure inside the cylinder to improve combustion at the time of the main stroke. However, by dividing the main injection into a number of smaller injections, a MultiJet engine affords a fuller, more gradual combustion whilst the amount of diesel burnt at each stroke remains the same. This promotes smoother, quieter combustion, reduced emissions and increased performance.

A MultiJet engine differs from its UniJet counterpart in two essential areas: the injectors and the electronic control unit.

To facilitate multi-injection, the new injectors can both reduce the time lag between injections from 1500 to just 150 microseconds, and reduce the minimum quantity of fuel injected from 2 to less than 1 mm3. In tandem, the new control unit modulates injection strategy continually to adjust to changes within three parameters: engine rpm, torque required at any given time by the driver, and coolant temperatures.

Thus, when coolant temperature is less than 60 degrees and torque requirement low, two small and one large injection are performed. As torque demand increases,the number of injections drops to two; one small and one large. Under conditions of high rpm and high torque demand, only one injection is required while, with coolant temperature at over 60 degrees, emissions are minimised with one small, one large, then one small injection in the sequence.

Start-up times and exhaust smoke are significantly reduced; noise levels and vibration are lowered to ensure a quieter drive and improved passenger comfort; fuel consumption is reduced by a further 10 per cent and emission control reduction is greatly enhanced.

The compact, efficient and reliable 75 bhp 1.3 16v MultiJet engine is extremely eco-friendly, thanks to an emissions control system which features an electronically triggered Exhaust Gas Recirculation valve managed directly by the engine control system, a heat exchanger to cool recirculating exhaust gas and a close coupled catalytic converter. Also fitted as standard is a particulate trap (DPF) – a ‘for life’ system that needs no regenerating additives.  This is a mechanical filter, integral with the exhaust system, that physically traps particulates in the diesel engine’s exhaust gases.  It almost totally eliminates particulates in compliance with current and future legal regulations.

TRANSMISSIONS
A range of reliable, robust and sophisticated gearboxes has been developed to match the new Fiat 500 engine range; a 5-speed manual gearbox mated to the 1.2 litre FIRE petrol and 1.3 16v MultiJet powerplants, and a 6-speed manual gearbox mated to the 1.4 litre FIRE petrol engine. Dualogic, an innovative, power assisted, semi- or fully-automatic transmission is available with the 5- and 6-speed manual gearboxes of the 1.2 and 1.4 litre FIRE petrol units.

A light, accurate gear change has been effected by the reduced inertia of the driven clutch plate and the introduction of new seals. The gear casings, developed using finite element structural computing methods, are light yet display high noise absorption efficiency. Fifth speed and final drive gear sets are machined to a superfinish after heat treatment, to further reduce noise levels.

Both gearboxes feature a dual cable external control that filters engine vibrations transmitted to a dashboard-mounted gear lever offering outstanding selection manoeuvrability, hydraulic clutches are used to promote ease of use, efficiency and low running noise, and a ‘syringe’ mechanism is employed to prevent involuntary reverse engagement.

Dualogic
The innovative Dualogic transmission system features a servo automated clutch and gear lever, while retaining all the attributes of a dry clutch and manual gearbox; low weight, strength, reliability and fuel economy.

Two operating modes are selectable; semi-automatic and automatic. In the absence of a clutch pedal, fast, accurate gear changing in semi-automatic mode simply requires the movement of the lever forward to change up and back to change down.

Once the new Fiat 500 has been started, brake pedal pressure allows the selection of either first or reverse gear (second gear may be selected to aid traction in slippery conditions). To ensure safety and prevent unsolicited gear changes, the system automatically engages neutral when the engine is still running and the door is
opened. Dualogic also prevents gear changing errors that risk damage to engine or transmission, reinforced with both visual and aural alarms.

In fully automatic mode, Dualogic offers two options: Normal and Economy. The Normal option offers outstanding driving comfort through the smoothest gearchanges under all conditions. Pressing the Economy button on the gear control panel offers reduced fuel consumption whilst maintaining driving comfort.

The Dualogic system offers the ideal compromise for those who prefer an automatic gearbox for day-to-day use, but do not wish to relinquish the driver involvement and satisfaction of a manual change.

RIDE AND HANDLING
Allied to a bodyshell of exceptional torsional stiffness, the new 500 employs a derivation of the highly acclaimed Fiat Panda’s proven suspension set-up within a wheelbase of 2300 mm and with the front track increased by 36 mm and the rear by 40 mm. The combination of an independent MacPherson strut front configuration and a lightweight torsion beam axle at the rear offers a high level of driving precision, roadholding and ride comfort.

The front MacPherson strut suspension layout features transverse lower wishbones anchored to an auxiliary crossbeam, an anti-roll bar connected by rods to the shock absorbers (a first in this category), new design coil springs that increase the absorption of minor surface roughness, and wishbones with both front bushes and new vertical rear bushes of rubber and metal. The new bushes contain an increased percentage of rubber, offering an excellent compromise between vibration suppression and road adhesion.

The rear suspension configuration combines a folded sheet steel torsion beam with double acting telescopic hydraulic dampers located beneath the floor to improve comfort without compromising load space. Single rubber and metal bush attachment of the rear axle to the body further lowers noise and vibration intrusion into the passenger compartment, while promoting greater driving stability under all conditions by generating a wheel toe-in effect during cornering.

The new Fiat 500 is equipped with Dualdrive electric power assisted, rack and pinion steering requiring 2.5 turns lock-to-lock. 1.2 8v FIRE and 1.3 16v MultiJet models have a turning circle of just 9.2 metres, while the 1.4 16v FIRE version has a turning circle of 10.6 metres.