The Global Small Engine engines. The turbocharger that forms the basis of the new e-Hybrid is a four-cylinder Gse, acronym for Global Small Engine. This family of engines, also known as FireFly, was designed to replace Fire engines and TwinAir (the two-cylinder Sge, Small Gasoline Engine) globally: born in 2016, it debuted in Brazil in two displacement variants. – 72 bhp 1.0 N3 and 101 bhp 1.3 N4, both naturally aspirated – on models such as the Fiat Uno, the Mobi and, later, the Argo. Versions for South America can also run on ethanol and feature indirect injection, a single overhead camshaft with variable valve timing and two valves per cylinder. For the European market, the two four-cylinder with aluminum crankcase have been updated in the cylinder head and in other details: the T3 of 999 cm3 (120 HP) and the T4 of 1,332 cm3 (150 or 180 HP) arrived in 2018 are characterized by supercharging. by turbine, direct injection and MultiAir 2 distribution with four valves per cylinder. These units formed the basis of the first hybrid models of the Fiat brands (the three-cylinder 1.0, aspirated version with 70 HP made its debut on the Panda and 500 Hybrid) and Jeep (with the 4xe versions driven by the 1.3 turbo).
The (new) thermal Gse. The four-cylinder around which the new hybrid architecture was developed has an increased displacement: the 1.5 Gse T4 Turbo e-Hybrid has a bore of 71.2 mm and a stroke of 92.2 mm for a total of 1,469 cubic centimeters. Also in this case the crankcase is made of aluminum (being shared with the T4) and the distribution has a double phase variator, while the high pressure direct injection system (350 bar) is new and the high turbulence intake ducts have been redesigned. The millecinque exploits a Miller operating cycle (therefore with a shorter compression phase than the expansion phase, to increase the energy derived from the pressure generated by combustion, ed), for a compression ratio of 12.5: 1 (1.3 reaches 10.5: 1). The maximum power is the same as the 1.3, 130 hp, but it is delivered higher (5,500 rpm instead of 4,750), while the torque drops to 240 Nm at 1,500 rpm (the smaller “brother” reaches 270 Nm at 1,560 rpm). The power and torque of the thermal are the same as the entire hybrid powertrain: the electric part, in fact, mainly intervenes at low speeds, without changing the maximum values measured.