This 2012 Audi five-door derivative is called the A1 Sportback and is significant not only for its styling and added practicality, but also for a new engine that’s available on this car first. That unit is a new 1.4-liter TFSI making 140 hp. It features cylinder-deactivation technology, a first in a nonhybrid four-cylinder. Only when needed, all four cylinders work together to move the car forward in a hurry or to provide engine braking; at partial loads, two cylinders are deactivated by pushing zero-lift cam profiles over the valves of cylinders two and three.
Cylinder deactivation is standard on Audi’s and Bentley’s 4.0-liter, twin-turbocharged V-8. Those cars get some high technology to go along with it: active engine mounts, which counteract vibration using out-of-phase counter-oscillations, along with a speaker-based noise-cancellation system. When changing between the two modes, extra fuel is injected to smooth out the transition.
With the 1.4 TFSI, Audi does without those active systems because they would be far too expensive for this class. Nevertheless, the engine works great. It is not only powerful and responsive with very little turbo lag, but also fuel-efficient. Cylinder deactivation helps reduce consumption by roughly ten percent, according to Audi.
The transition from four- to two-cylinder mode is announced in the instrumentation, which is helpful, as it is virtually undetectable to the driver. We saw indicated fuel consumption in the low-40-mpg range, all the while appreciating the sonorous quality of this utterly enjoyable powerplant.