Take a brief break from enjoying the fabulous new green cars on display at the Geneva Motor Show and look a little deeper at the technology on display and you’ll quickly discover what is driving the cars of the future.
Among the most notable technological advances unveiled is the new air management technology Multiair, an electro-hydraulic valve-timing system from Fiat that provides dynamic and direct control of air and combustion, stroke by stroke and cylinder by cylinder.
According to Fiat, the Multiair, along with direct control of the air through the intake engine valves, can help to reduce fuel consumption by as much as 10 per cent in turbocharged or naturally aspired engines. Indeed pollutant emissions are also reduced.
So how does it work?
The operating principle sees a piston moved by a mechanical intake cam, connected to the intake valve through a hydraulic chamber. This is controlled by an open on/off solenoid valve. When this valve is closed, the oil in the chamber acts like a solid and transmits to the intake valve the lift schedule imposed by the mechanical intake arm. When the valve is opened, the chamber and intake valves are de-coupled with the intake valves no longer following the intake cam. The final part of the valve closing is controlled by a hydraulic brake for soft and regular landing phase.
The benefits of this system are far-reaching with maximum power increased by 10 per cent; low-rpm torque improved by as much as 15 per cent; a 10 per cent reduction in fuel consumption and CO2 emissions; and Multiair turbocharged and downsized engines could even achieve a 25 per cent fuel economy improvement over conventional engines.
