Previously, the five-door Giulietta was available with a choice of petrol engines and two diesel MultiJet engines in 1.6 and 2.0-litre capacity.
The MultiJet engines, designed to boost power while improving fuel economy, are designed by Fiat Group and are used in both the Alfa Romeo Giulietta and Alfa Romeo MiTo supermini.
The latest addition to the range is a 2.0-litre MultiJet diesel delivering 140bhp – 30bhp less than the more powerful 2.0-litre engine currently available.
Alfa says the engine offers the most torque in its class with 350Nm at 1750rpm for cars with similar efficiency and power stats.
The Giulietta is capable of an impressive 62.8mpg on the combined cycle and CO2 emissions of 119g/km, but delivers a top speed is 127mph and it is capable of hitting 62mph from standing in nine seconds.
In terms of road tax, the new engine will qualify from an exemption for first year road tax and will be on one of the lowest rates after 12 months.
The CO2 emissions figure is boosted by Start&Stop technology included as standard with the 2.0-litre powerplant. Other green technologies include a diesel particulate filter to reduce harmful exhaust pollutants and a gas recirculation system to aid gas flow and improve efficiency.
The new range of engines and technology comes at a time when Alfa Romeo is shedding its reputation for stylish but unreliable cars by offering a 21,000 servicing interval to show its confidence in the quality of the build.
Alfa’s Ford Focus rival will be available with the new, efficient engine immediately. The engine will be offered on Lusso and Veloce specification models priced at £20,750 and £20,050 respectively.