The range centres around a pair of 1.4-litre TB Multiair petrol engines. The low-power unit develops 135bhp at 5250rpm and 152lb ft at 1750rpm, while the high-power version develops its 170bhp at 5500rpm and 184lb ft at 2500rpm.
Both engines offer excellent flexibility and economy. Variable air intake technology means that you can use fifth gear at 30mph around town at just over 1000rpm and the engine never feels as if it is about to stall; it still offers acceleration.
Benchmark performance figures are competitive, with 0-62mph times of 8.4 and 7.4sec and top speeds of 129 and 136mph for the 135 and 170bhp versions respectively. But that high power engine comes with a significant price penalty as it is only offered in the range-topping Veloce model - previously known as the Quadrifoglio Verde.
The other petrol-powered engine is a version of the Fiat Group’s Twinair engine. Tweaks launched in late 2013 saw power climb from 85bhp to 105bhp, with comparable on-paper running costs. To the ears of an enthusiast, the engine sounds characterful and is keen to rev, but to others it is noisy and coarse.
It makes best use of its power high in the rev range (peak power comes at 6500rpm), but it runs into a soft rev limiter shortly after. Changing up drops the car to around 4000rpm, creating a very narrow operational rev band.
The JTDm 1.3-litre diesel was recently revised so now it produces 10bhp than before - now a heady 93bhp and produces lower emissions too. The engine is sufficiently refined until demands are placed on it high in the rev range, when it becomes noisy.
Unfortunately, the abilities of all engines are often masked by Alfa’s DNA system - a creation, we suspect, of Alfa’s marketing men. A toggle switch gives the Mito driver a choice of three modes: Dynamic, Normal and All-weather, each changing the electric power steering, dampers, throttle map, traction control and, on turbocharged models, the boost pressure.
It is the throttle response that causes most frustration. In normal mode, it is very spongy and requires a lot of travel before the engine finally responds. Dynamic mode improves it dramatically, with a much more immediate response that is easier to modulate. Why the throttle response isn’t always in this setting is a mystery.