Our cars: Audi A3 Saloon hello

Our latest long-termer is a car that has shaken an entire market segment to bits. For years, if you wanted an executive saloon, your choice was basically between the BMW 3 Series, the Mercedes C-Class or the Audi A4 (with a sideways glance at the occasional Lexus). Now, though, you can also opt for the Audi A3 Saloon – and the car's blend of low running costs and a beautifully finished cabin was enough to win it the What Car? Executive Car of the Year Award back in January.

Traditionalists might grumble about this, of course, because while the A3 Saloon has the traditional three-box shape, it is undoubtedly a smaller vehicle than the established order. However, our road testers' view is that it's big enough for most daily requirements, and that the rest of its benefits – running refinement, a gorgeous cabin and impressive running costs – outweigh the final few litres of boot space that you're sacrificing.

Still, we're keen to see if this theory is borne out over a longer period than a group test - which is why a white A3 saloon has just turned up in our car park. We've gone for the same 2.0 TDI Sport specification that lifted the Executive Car title. However, since Audi's supply chain is running at full tilt, we had to compromise in some areas to get a vehicle this side of autumn.

That means our car was plucked from Audi's stock lists - so it has a few more options than we'd normally go for. You can start with the Glacier White metallic paint and the Black Milano leather seats, and then add adaptive cruise control, the Technology Pack (hard disk-based sat-nav), the Comfort Pack (rear parking sensors, rain-sensing wipers and auto-dimming rear-view mirror), heated front seats, an upgraded sound system, Audi's parking system upgrade and something called 'pre-sense' which tries to detect an impending impact and sets up the car's systems accordingly.

The end result is a price, including delivery, of £29,815; that's steep for an A3 but around the same as a BMW 320d before options. In any case, the Audi's core values – torque-laden 2.0-litre four-cylinder diesel, six-speed manual gearbox and CO2 emissions of only 107g/km – are all present.

We haven't wasted any time in putting them to the test, either. Our car arrived with just 89 miles on the clock but we've already raced up beyond 2000 miles, thanks to a couple of family trips to Norfolk and a week's hard work on our Tow Car of the Year judging sessions.

My early thoughts? The boot is actually a decent size and a good shape, and the rear seats have good access; my 6ft son jumps in and out with ease. The 2.0-litre engine is still loosening up but it's returning 48mpg already; I'm hoping that it'll soon nudge beyond the 50mpg mark, delivering a potential real-world range of more than 530 miles per tank.

Oh yes, and the cabin is a joy to behold. I'd heard from John McIlroy, who ran the A3 Sportback for a year, that the Audi's fascia is a pretty special thing, and I can already see what he was banging on about. It's simple, uncluttered, easy to use and beautifully built.

Will that last? Or will the Audi's slightly more humble origins rub through as the miles pile on? It's going to be an interesting test.

Logbook
Audi A3 Saloon 2.0 TDI 150 Sport

Buying information
List price £24,275
Target Price £22,713
Extras Technology package (£1495); Black Milano leather (£1115); Comfort package (£605); Glacier White metallic paint (£525); Adaptive cruise control (£350); Heated front seats (£260); Audi sound system (£255); 17-inch alloy wheels (£250); Audi parking system plus (£250); Audi pre-sense basic (£200); Storage and luggage pack (£145); Hold assist (£90)
Price as tested £29,815

Running costs
Official fuel economy 68.9mpg
True MPG 51.2mpg
CO2/tax liability 107g/km/17%