Start with what the Alfa Romeo 146 is: a car with gasoline engine, from Alfa Romeo. What it meant takes a little longer. 233,295 were built.
Under the skin
The engine is gasoline engine. These are manufacturer figures carried by Wikipedia and Wikidata, not road-test measurements.
In context
Nearby in the Alfa Romeo catalogue sit the A.L.F.A 12 HP and the A.L.F.A 15 HP.