Двигатели Multijet: Технологии и особенности дизельных моторов Stellantis.

Multijet is Stellantis's term for its current common rail direct injection turbodiesel engine range. Most of the Fiat, Alfa Romeo, and Lancia range, as well as certain Chrysler, RAM Trucks, Jeep, and Maserati vehicles, are equipped with Multijet engines. Ownership of some Fiat Multijet designs is shared with General Motors as part of a settlement of the failed merger between the two auto conglomerates. The GM Powertrain Torino group in Turin, Italy, manages its interest in these engines. Some PSA Peugeot Citroën diesel engines are also rebadged JTD units, and vice versa. Fiat's common rail diesel engine is also known as JTD, an initialism of Jet Turbo Diesel.

The property that distinguishes the Multijet from previous generations of common rail diesel engines from FCA is the combustion of the fuel, which is split into multiple injections, thus allowing for a more complete, quieter combustion in the cylinder. Compared to the first generation JTD engines (Unijet system) which only featured a smaller pilot and a larger main injection, Multijet is capable of up to five injections per combustion cycle which enables better, more efficient cold running, better performance especially in the lower rev range, quieter operation as well as even lower consumptions and emissions. The time between injections has been reduced to 150 microseconds while the minimal injection quantity has been reduced from two to less than one microlitre. This enables even mid sized sedans like the Alfa Romeo 156 and Lancia Lybra equipped with the 1.9L JTD to achieve fuel economy upwards of 45 mpgUS (55 mpgimp or 5L/100 km) on country roads and highways while offering an equal amount of torque as the 3.0L 24V V6 engine. A sophisticated electronic control unit controls the injection and changes the injection logic and number of injections based on a multitude of parameters, most importantly revolutions per minute of the engine, engine torque requested by the driver and the temperature of the coolant. The injection pressure of the diesel fuel on the second generation Multijet is limited to between bar ( psi) on the 1.3 Multijet and bar ( psi) on the 2.4 Multijet 20V.

In 2009, Fiat Powertrain introduced the third generation of this technology, called Multijet II. With its new and innovative injectors with hydraulically balanced solenoid valve and even higher injection pressure of 2,000 bar (29,000 psi) it is capable of even more precise controlling of the injected diesel fuel, injecting it in a quicker and more flexible manner. It enables up to eight consecutive injections per combustion cycle and implemented Injection Rate Shaping technology, which provides two very close pilot injections making the fuel delivery more continuous and modulated. This results in an engine that is quiet and has a smoother operation, lower emissions, better fuel mileage and higher performance compared to the previous generation.

The most common JTD engine is the 1.9 L straight 4 found on various brands and models. The first car that used this engine was Alfa Romeo 156 in 1997 , making it the world's first common rail diesel passenger car. In 1999, it was introduced on the Fiat Punto JTD with a smaller, fixed geometry turbocharger and , as well as in the Fiat Brava, Bravo and Marea range. There were also , , , , and versions available. The engine block weighs approximately , the cylinder head features an overhead camshaft with directly actuated valves. The Multijet second generation features an advanced common rail system and is available with seven different power outputs. The 8 valve version has , , or and the 16 valve version has , , , or Except for the 101 PS Multijet, all engines feature a variable geometry turbocharger. Opel also uses a version of this engine. Their CDTI engine, manufactured in Pratola Serra, Italy and Kaiserslautern, Germany, is the product of the half decade joint venture between GM and Fiat. It is used in the Vectra, Signum, Astra, Zafira, Cadillac BLS and Suzuki SX4 as well as some Saabs marked as TiD and TTiD (twinturbo version).

See VM Motori A 630.