Fiat adds fuel-saving MultiAir technology to Alfa Romeo MiTo

Fiat is keeping using technological breakthroughs to improve both performance and efficiency in diesel engines. More power, reduced fuel consumption, and lower exhaust emissions, these are features of Fiat’s new technology for petrol engines. The new technology is called MultiAir.

Compared to a traditional petrol engine with the same displacement, MultiAir engines ensure an increase in power (up to 10%) and torque (up to 15%), as well as a considerable reduction in consumption levels (up to 10%) and CO2 emissions (up to 10%), of particulates (up to 40%) and NOx (up to 60%).

The MultiAir engines will be on offer on the Alfa Romeo MiTo starting in September. The MiTo will be available with the MultiAir 1.4 liter 16v engine in three variants, both turbocharged and normally aspirated. Power levels will be 105, 135 and 170 hp and engines will be coupled to both 5 and 6 gear manual transmissions. The 105 and 135 hp variants will be offered on the entire MiTo range while the 170 hp version will be a special edition called the Quadrifoglio Verde MiTo (Green Four-Leaf Clover) which will debut sometime after the launch of the MultiAir system on the MiTo.

The heart of the MultiAir is the new electro-hydraulic valve control system which makes it possible to reduce fuel consumption and polluting emissions. The key to controlling petrol engine combustion, and therefore performance, emissions and fuel consumption, is the quantity and characteristics of the fresh air charge in the cylinders. In conventional petrol engines the air mass trapped in the cylinders is controlled by keeping the intake valve opening constant and adjusting upstream pressure through a throttle valve and camshafts.

One of the drawbacks of this simple conventional mechanical control is that the engine wastes about 10% of the input energy in pumping the air charge from a lower intake pressure to the atmospheric exhaust pressure.
MultiAir is unique in that it uses an electro-hydraulic system to actuate the valves as opposed to the more common electro-mechanical setup. This relatively simple system can alter the timing of the valve's opening and closing in relation to how much power or efficiency is required at any specific moment. Additionally, it draws very little power from the engine.

In the future, MultiAir technology could see its introduction on Fiat's diesel engines.