Inside the cylinder head of a MultiJet II engine
Fiat is a leader in Diesel engine technology. Fiat invented the revolutionary Common Rail diesel technology for passenger cars. Now Fiat is introducing MultiJet II...diesel technology that promises to make an impact as large as Common Rail did in 1997.
In 1997, Fiat introduced the Common Rail (called JTD or UniJet Turbo Diesel by Fiat) . By upping the fuel pressure, changing injection design and adding a pilot or pre-injection of fuel, Common Rail changed diesel engines forever. This pre-injection of fuel allowed Fiat to tame the characteristics of diesel engines, which, up to then, where known for noisiness, smokiness, poor response and low horsepower output. All at once, out went these "uncivilized" manors and in came a new degree of smoothness, quietness and power. As a result, diesel sales of passenger cars in Europe went up from 15% to 50%.
The 1.3L Multijet Fiat 500 engine
In 2003, Fiat upgraded the Common Rail (JTD) to MultiJet technology. This advancement brought the number of pre-injections to a total of 5 and ushered in even more refinement and performance. Fiat combined MultiJet, turbocharging and a 1.3L diesel engine and came up with a jewel that went on to win the 2005 "International Engine of the Year Award". Previously, the expression "fun to drive" and "1.3L diesel" were never used in the same sentence. This is one of the optional engines available in the Fiat 500.
The Lancia Musa is one of the first cars with MultiJet II
Now, in 2009, Fiat does it again, with MultiJet II. This is the ultimate evolution of its Commom Rail technology. The highlight of this technology is pre-injections are now at up to 8 injections per cycle, bringing refinement to an all time high. The added pre-injections of fuel let the Fiat engineers precisely tune the engine for many variables... noise, vibration, harshness, fuel economy, power and emissions are all improved. Additionally, the MultiJet II injectors have been simplified, made more efficient, responsive and also easier to manufacture. MultiJet II plays up all the advantages of a diesel (fuel economy, relative simplicity and good torque) and lends itself especially well to small displacement engines.
The MultiJet II breakthrough is even more significant because of the time it is being introduced. Interest in fuel economy is at an all time high and, now with the ability to precisely meter the fuel in a way that previously was impossible, makes a small displacement diesel engine very attractive.
The Fiat MultiJet II Diesel Engine
When Fiat brings MultiJet to America, it promises to make Chrysler a leader in diesel technology. No one in the the US is currently utilizing small displacement diesel technology and this would help Chrysler stand out from the crowd. A high output, fun to drive turbo diesel car, with none of the negative characteristics of diesels of old, would be an attractive alternative to people looking at a hybrid-electric car. Diesel technology, even if it is advanced, is still a relatively simple, known technology and is more familiar to people resistant to unfamiliar, complicated hybrid-electric technology.
We'll see how MultiJet II fits into Chrysler's five year plan when they announce its details on November 4th.
Below is a more detailed explanation of Multijet II taken from the Punto Evo's press release, courtesy of Fiat:
The New Fiat Punto EvoAll Fiat Punto Evo diesel engines are equipped with the next-generation MultiJet II Common Rail injection system. This highly advanced solution can control high engine pressures (up to 1600bar) without being tied to engine speed or the quantity of fuel injected.
In the 1.3 MultiJet II Euro 5 versions, the system uses innovative common rail injectors that, thanks to a balanced hydraulic servo-valve, are able to more precisely control the quantity of diesel injected into the combustion chamber, with a faster and more flexible sequence of injections than was previously possible.
By reducing the amount of time between injections, these injectors optimize fuel introduction to the chamber and therefore make the diesel combustion process more gradual, with positive effects for consumption, emissions, NVH and handling. In fact, the new common rail injector on the Euro 5 engines cuts consumption and CO2 on the approved cycle by around 2%, while at the same time reducing harmful emissions.
The second-generation MultiJets are therefore the latest development in the Common Rail injection system which, after the JTD (1997) and MultiJet (2003) engines, gives the Fiat Group yet another first in this field.
The 1.3 MultiJet is available in Euro 4 (75 and 90 hp) and Euro 5 (75 and 95 hp) versions, the latter coming with a particulate filter and Start&Stop as standard. In addition, turbo is carried out either by a fixed geometry turbocharger (75 hp) or a variable geometry turbocharger (90 and 95 hp).
The Euro 5 versions have next-generation turbochargers that, combined with the new second-generation MultiJet II injection system, ensure the best possible turbo function at any engine operating level, with torque delivery at low revs up to 25 per cent higher than on Euro 4 versions.
The performance levels of the 95 hp second-generation 1.3 MultiJet (Euro 5) are well worth a mention: top speed of 178 km/h, 0-100 km/h in 11.7 seconds, consumption of 4.2 l/100 km and 110 g/km of CO2 emissions (in the combined cycle). When combined with the Dualogic gearbox, consumption falls to 4.1 l/100 km and emissions to 107 g/km.
Finally, the Punto Evo range retains the brilliant 120 hp 1.6 MultiJet Euro 5 with DPF from the previous model. With this engine, the car can reach a top speed of 193 km/h (Sport version) and go from 0-100 km/h in 9.6 seconds. Excellent performance also comes with reduced consumption and emissions: in the combined cycle, these figures are 4.5 l/100 km and 119 g/km of CO2 respectively.
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