Like all popular cars, the Uno has remained loyal to the 1.0 engine since the 1980s, with power outputs of 52 hp, 58.2 hp, and 59.7 hp for the S and SC versions. The new Fiat Uno arrived with a 1.4 Fire Evo engine, with improvements over the 1.4 Fire previously used by Fiat. This engine delivers 85 hp at 5,750 rpm.

Back in 2014, with the already restyled Uno version, it debuted with the 1.0 Fire Evo four-cylinder engine, from the Fiat Uno Attractive version. It had 73 hp of power at 6,250 rpm with a five-speed manual transmission. Of the engine variations that Fiat has used in the Uno, in addition to the Fire Evo, there is also the FireFly, in 1.0 and 1.3 versions.

Perhaps you already know, but the Uno's reputation as a "durable" vehicle is due to its high fuel economy. Rated A by Inmetro (Brazilian National Institute of Metrology, Quality and Technology), the Fiat Uno, more precisely the Uno Mille, achieves a fuel consumption of 12.7 km/l in the city and 15.6 km/l on the highway, and some owners on online forums report achieving over 20 km per liter, which is phenomenal! The Uno Mille became a benchmark car for the lower classes of society; owning a car was no longer an impossible dream for these citizens.