With such a light load to lug, performance is much better than you might expect considering either engine's diminutive capacity, but it also means they are both mega-economical. Even in petrol form the A2 manages to sip a gallon of fuel only every 47.1 miles - the diesel averages nearly 66mpg; with a smallish 7.5-litre tank, the petrol A2 has a range of 352 miles and the TDI can go for nearly 500 miles between stops.
With such frugality, logic dictates that the Audi A2 must also be amazingly clean - and it is: at just 116g/km, the Audi A2 TDI is the second cleanest car on sale in the UK behind the MCC Smart at 115g/km, with only the new breed of petrol/electric hybrids in the shape of the Honda Insight and Toyota Prius in front. In petrol format, the A2 records 144g/km.
But these pictures do not do justice to the A2's tiny proportions. At 1.67 metres wide, it's 13cm narrower than a Ford Fiesta and standing 1.55m tall it is 17cm shorter than a Renault Scenic. To counteract any inherent packaging deficiencies, Audi has engineered a Space Floor Concept. Unlike the Mercedes-Benz A-class's sandwich floorpan approach in which the engine and transmission sit below the floor leaving a flat top section for the seats and load area, Audi has attempted to match the brief without plagiarising the formula with a split-level floor in which the rear-seat passengers sit below the front pair, thus liberating rear headroom and kneeroom. Like the A-class, the A2 is amazingly space-efficient and easy to get in and out of compared with other small to lower medium hatchbacks.
And yet it is as people-carrier-friendly as a Renault Scenic, Citroen Xsara Picasso or Mazda Premacy. To meet the growing demand among user-choosers for MPV-style vehicles, the A2 offers a hugely versatile and practical interior including rear seats that fold forward or can be removed altogether, and a useful secret box in the loadfloor.
Entry-level pricing for the new A2 starts at £13,950 on-the-road for the A2 1.4 rising to £15,100 for the A2 1.4 TDI; SE specification adds another £1,780.
The 1.4-litre 16v 'four' revs keenly accompanied by a familiar exhaust note. The biggest difference, though, compared with the A2 TDI is in-gear flexibility and it's here where the TDI starts to stride ahead. In any other midi-MPV the 5,800rpm rev limit wouldn't be a problem but for the fact that the A2 petrol's power doesn't peak until the 4,000rpm mark, after which you're left with precious few revs to play with. And so it proves with the torque figure. Peak torque on the petrol A2 is generous at 125lb-ft but again this is set fairly high at 3,800rpm - the TDI's, however, is firstly more powerful at 194lb-ft but also at a much more user-friendly 2,200rpm.
Consequently, the A2 16v is no fireball - as illustrated by the 0-62mph time of 12secs. But unless you regularly moonlight as a taxi driver, the rest of the 1.4 16v's repertoire is entirely convincing. Cruising at the legal limit is a refined and relaxed experience and even though quick overtaking manoeuvres require rapid downchanges, this is never a chore because the five-speed gearbox's light and precise action is the best of any in the current Audi crop.
And so too is the ride and handling. All A2s (and all revised A3s) gain the Electronic Stability Programme (ESP). But unlike the A-class's infuriating intervention at even a sniff of a corner, the A2's chassis is much better sorted, zipping round corners with incredible agility. Also a marked move away from Audi traditions is the quality of the brakes which are strong and progressive.
Make no mistake, just because Audi has concentrated (and spent all its money) on exploring the boundaries of structural and engine design more than most, doesn't logically mean the A2 is any less meticulously finished or as solid as any other Audi - just different. Some interior plastics may not feel as expensive as those draped across an A4 or A6 - but then the A2 isn't anywhere near as expensive as either sibling.
Sitting in the lofted driving position gives a commanding view of the road ahead and even this doesn't erode the A2's 'chuckable' feel. Given the material used for the underbody, one might have expected more exposed aluminium inside, but the A2 makes do with a set of elegantly-rimmed dials, door handles, gearlever surround and handbrake knob - and even these are part of a £140 aluminium pack option.
Thanks to the split-level floor, rear legroom is generous and despite the sharply-sloping roofline, so is headroom; at the same time the A2's narrow proportions mean this is a strict four-seater.
Unique, though, is the lack of a spare wheel. With its economy-minded approach, the extra weight would have diluted both the performance and the frugality; instead Audi provides a pump-type tyre repair kit - for peace of mind a spare wheel can be ordered as a no-cost option on SE models and effectively fills the hole beneath the load floor.
The standard equipment list includes 15in aluminium alloy wheels, height and reach-adjustable steering column, traction control, twin and side airbags, ISOFIX child seat fixings and remote locking. SE versions add 16in alloy wheels, full climate control, front fog lights and luggage cover.
Niche vehicles like the A2 rarely strike a chord with fleet operators due to flimsy residual values, low stock availability, high purchase prices and cataclysmic running costs. But the A2 is different.
Audi predicts 75 per cent of A2s will go to fleets - and it's easy to see why. With carbon dioxide emissions at just 144g/km, the A2 1.4 16v easily beats the Scenic 1.4 16v Aliz_ at 168g/km and the Mercedes-Benz A140 Elegance at 174g/km.
The A2 1.4 16v goes on sale on September 1 and Audi plans to sell just 600 units this year with a further 1,100 petrol models earmarked for 2001; even with the 750 TDIs this brings the total UK allocation next year to only 1,850.
With such a limited run, then, and with a guarantee from Audi that no A2 models will find their way on to daily rental fleets (unlike easyRent-a-car's A-classes), CAP Monitor predicts a healthy residual value over three years/60,000 miles of £5,800 - or 37 per cent of cost new.
The A2's will also feature Audi's Variable Servicing Interval Programme (AVS). With this, drivers are no longer constrained by fixed service intervals - instead sensors fitted to this car and all 2000 model year Audis monitor the driving style of each owner and personalise the service intervals accordingly.
Average use now means a petrol A2 can go for two years or 19,000 miles before a major service - the TDIs can push this up to 30,000 miles.
It's a hoot to drive cross-country with a ride and handling balance that belies its midi-MPV origins; but the changes go much further than this: modifications to the steering, brakes and gearchange make the A2 one of the most rewarding Audis to drive. It is also well built with a high standard equipment and safety specification and strong residual values.
But the A2's raison d'_tre is its economy: on price, at the pumps and at the tailpipe. It's also amazingly economical and clean. At the end of the day, if you crave the versatility of an MPV without letting your colleagues know you've got one, choose the Audi A2.