Balocco (italy), 10. September 2009 – the fiat group wants nothing less than a revolution – at least as far as the new valve control system for gasoline engines for the cars from turin and milan is concerned. The so-called multiair technology is supposed to reduce fuel consumption and at the same time provide more torque and plug the turbo hole. Sporty engine sound as a bonus. We took the opportunity to try out whether this supposed squaring of the circle holds in practice what fiat promises – namely in an alfa mito 1.4 tb 16v with 135 hp, where it is used first.
Units with 135 and 170 hp
Three multiair engines are destined for the mito, although only the two more powerful ones are used in germany. All three units have a displacement of 1.4 liters. The weakest version with 105 hp is a naturally aspirated engine and will not be introduced in germany for the time being. This will be followed by a 135 hp turbocharged version, which will replace the previous 120 hp turbo with immediate effect. A 170 hp version can be ordered from december 2009, which will then represent the new top engine version. The 1.4-liter multiair engines will also be available in the fiat punto evo at the end of the year.
Pumping losses eliminated
The multiair technology is an electrohydraulic valve control system for the intake side. The camshaft is no longer exclusively responsible for the valve lift and the opening and closing timing. For lower power requirements, this control task is taken over by an electrohydraulic system instead. The cylinder filling is determined by the intake valves, not by the throttle valve. This eliminates the pumping losses caused by throttling in conventional engines, which makes the engine more efficient. According to the data sheet, the mito consumes 5.6 liters per 100 kilometers – half a liter less than the 120-hp turbo that was sampled. However, the automatic start-stop system, which is standard in the new multiair models, also helps save fuel. Not in the standard consumption data, but in everyday use the gearshift indicator reduces fuel consumption. It is also standard on the multiair models.