The injector is located in the cylinder head on the intake side and is supplied by a high pressure pump driven by the camshaft and a single distribution pipe, the common rail system. The injector controls the injection time to within thousandths of a second, at pressures of up to 110bar. By comparison, indirect injection operates at a max of eight bar.

Sounds pretty straightforward so far. Fire it up and you won't notice anything unusual: this 1.6 idles almost imperceptibly and stays quiet at low speeds, which is an improvement on the grumbling of the current 1.4. Mash the throttle, however, and as the rev counter passes the 4K mark a not-unattractive growling signifies the imminent arrival of the 4500rpm torque peak. This sudden transformation might have something to do with another clever element of the FSI system, the 'tumble flap'. It's part of the intake system, as Audi explains:

With the flap in the open position the air passes by unobstructed. In the second position the flap moves against the tumble plate, thus shielding the lower part of the intake port. This makes two operating modes possible: homogenous and stratified charge operation. Depending on load status and accelerator position the engine electronics switch to the optimum mode.

Still with us? Audi claims more engine computing power than an Apollo moon rocket - best hope it's not Apollo 13 or you might have concerns about making it back from Tescos - so that you'll never notice the engine shifting between homogeno-thingy and stratified whatsit. With 110bhp, albeit in a slimline 995kg body, the A2 FSI was never going to be a fireball but it clips along nicely in the real-world schlep, especially when you crest that high torque peak. On the autobahn the A2 settles into a comfortable cruise somewhere on the dark side of 100mph, at which speed the encouraging high-rev snarling becomes a more irritating migrane-in-waiting. It shouldn't trouble you in the UK. Big miles will be aided by a bigger, 42-litre fuel tank - which goes into all A2s - and by the FSI efficiency claims, even in power-optimised homogenous mode. Audi again:

At full load the fuel is injected synchronously with the air intake phase. However, due to the precision of the injection process, the extremely fine atomisation and the internal cooling effect when the fuel evaporates directly in the combustion chamber, the FSI engine can operate at a much higher compression ratio than an indirect engine. This results in greater efficiency.

Glad we got that one cleared up. The FSI also ushers in a series of A2-wide chassis tweaks, which are easier to understand. These include variable-rate springs - initially soft to help the ride, then firmer to sharpen the handling. Though they're a worthwhile addition, they don't turn the A2 into a handling paragon.

Yes, there's plenty of grip and slack-free steering but there's no real handling spark especially since the A2 can't escape that lolling cornering feel endemic amongst lofty cars. But at least they've buffed the edges off the firm ride and it's still a more satisfying chassis than Merc's A-class. Plus the dash is typically Audi-attractive and the interior a nice place to be, unless you plump for the optional and mightily horrid korma-coloured seats.

The A2 FSI isn't a keen driver's car, but then it never set out to be. Instead it introduces some worthwhile chassis refinements and showcases new engine technology that will become the backbone of Audi's petrol range. The best thing you can say about the FSI technology is that it's so good you won't even notice its homogeneous this, tumble flapping that and significantly higher lambda values the other. What you should know is that higher-powered FSIs are on their way, including turbos. This is the future - and you don't even have to know how it works.