Fiat Panda Aria Concept Car Features Downsized Engine, Hydrogen-CNG Blend Fuel and Stop-Start System

7 September 2007

Panda Aria concept.

Fiat will introduce its Panda Aria concept car at the Frankfurt Motor show later this month.

The concept car combines a new 0.9-liter twin-cylinder 80 bhp turbo engine from the new Small Gasoline Engine (SGE) family with a dual-fuel gasoline-CNG system designed to operate with a 70:30 mixture of methane and hydrogen. The twin-cylinder engine features Multiair electronic inlet valve control and is equipped with a stop-start device and coupled with the MTA (Manual Transmission Automated) gearbox. CO₂ emissions are an estimated 69 g/km.

The Small Gasoline Engine (SGE).

The basic new SGE 2-cylinder Multiair turbocharged engine delivers a 20% improvement in fuel economy compared to the larger, 1.2-liter naturally aspirated engine on A-segment vehicles. In addition to advantages in terms of consumption, the twin-cylinder engine also results in a 20% reduction in weight and 25% in volume inside the engine bay compared to a 4-cylinder engine with the same power output.

The SGE engine family adopts a crankshaft balancing system that significantly reduces vibration and noise levels compared to other two and three cylinder engines.

The Multiair system controls the air flow without a throttle valve, and therefore with a greater degree of flexibility than mechanical timing systems. The electro-hydraulic valve activation technology is based on the insertion, between the camshaft and the engine inlet valve, of an amount of oil (high pressure chamber) that can be varied by a valve, which in turn is controlled by a specific electronic control unit.

The Multiair electro-hydraulic actuation system (shown for a four-cylinder engine). Click to enlarge.

This allows the raising profile of the valve to be modified in response to the request for air from the engine and to the running speed. Different strategies can be employed (Early inlet valve closing – EIVC; Late inlet valve opening – LIVO; or Multi-Lift) to optimize combustion efficiency, with benefits in terms of power output, torque, consumption and emissions.

Air pressure upstream of the valves is always constant. This characteristic, combined with the high system activation dynamics (from partial load to full load in one engine cycle) allows the torque response of the engine to be increased without any delay, on both an aspirated and a turbocharged engine, increasing the ‘fun to drive’ factor.

On the Panda Aria the new twin-cylinder engine is combined with a dual fuel management system, with gasoline and a mixture of methane (70%) and hydrogen (30%); this solution also helps to reduce polluting emissions by guaranteeing more efficient, complete combustion.

The hydrogen-natural gas blend also makes it possible to increase the engine’s thermodynamic efficiency and to achieve combustion stability values that are better than those possible with methane alone, under certain operating conditions.

The stop-start system turns the engine off temporarily when the engine is idling and the vehicle is stationary, with fuel savings of up to 10% in the urban cycle. The instant the brake pedal is released or a gear is engaged, the system immediately re-starts the engine.

The stop-start system combined with the MTA gearbox ensures optimal management of gear changes and mechanical efficiency. The automated transmission lays the foundations of the management of the on/off status of the engine. By controlling the clutch, the system allows the internal combustion engine to be cut off from the transmission whenever traction is not needed and the engine can be turned off.

The interior of the Panda Aria is upholstered with natural fibers (cotton and linen), woven coconut fibre and biodegradable elements, while the exterior paneling is made of semi-transparent eco-resin and the structure is treated with opaque ‘totouch’ paint.

The car is fitted with experimental Pirelli tires with new compounds and new AOF (Aromatic Oil Free) textile weaves which guarantee limited drag but do not detract from dynamic safety performance (stopping distances and good handling on wet and dry roads).

A telematics system, based on the Blue&Me architecture, is wired to adapt to new infomobility services. It also incorporates original software which allows the consumption and emissions of each trip to be recorded on a USB pen drive, through the USB port of the Blue&Me system, so that the customer’s driving style can later be analyzed on a computer.

Resources:

• Fiat Powertrain presentation