Longer than the five-door A3 Sportback by just over 14 centimetres, wider by 11 millimetres and nine millimetres lower, the new compact four-door offers similarly passenger accommodation, complemented by 425 litres of luggage space with the rear seats in place – 45 litres more than its five-door counterpart.
Sport and S line versions sit low on their respective 17-inch and 18-inch alloy wheels thanks to sports suspension, but both can also be specified at no extra cost with more comfort-oriented standard suspension. They also share features including sports seats, the Audi drive select adaptive dynamics system, dual-zone climate control, the MMI radio incorporating an 11 millimetre-thick powered folding screen and DAB digital radio, preparation for SD card navigation, Audi Music Interface iPod connection, a Driver Information System and the Bluetooth mobile phone interface.
Interior highlights of the S line specification include part-leather-upholstery embossed with the S line logo and an S line sports steering wheel with perforated leather grips and shift paddles where S tronic is fitted. Outside, 18-inch alloy wheels, S line body styling and xenon plus headlights with LED daytime running lamps set the top model apart.
Full-LED headlights will also be available later in 2013 as an alternative to the xenon units in S line models and the halogen units in Sport versions. S line customers can also swap their sports suspension not only for the comfort-focused standard configuration, but also for an exclusive S line sports set-up which lowers the ride height by a further 10mm below the sports suspension for greater handling poise.
The strict dictate of 'Audi ultra' lightweight design is evident in the 1,250 kg kerb weight of the A3 1.4 TFSI Saloon that initially kicks off the range. Its 140 PS engine is one of three units to be available at launch, all of which bring together efficiency technologies including direct fuel injection, turbocharging, innovative thermal management and the start-stop system.
As well as a low 107 kg weight, this version of the 1.4 TFSI is also notable for its Cylinder-on-Demand technology. At low engine load, the system deactivates two cylinders to minimise mechanical effort and cut fuel consumption. As a result, combined economy tops out at 60.1mpg, while CO2 is pared back to 109 grams per km. Helped by its 250 Nm torque peak, the A3 Saloon 1.4 TFSI takes 8.4 seconds to accelerate from 0 to 62mph, and can reach 135 mph.
The 1.8-litre TFSI which is next in line produces 180PS and 250 Nm (184.39 lb-ft) of torque. It employs dual injection into the combustion chambers and the induction manifold, to deliver a broad spread of strong performance, but its headline figures are a 7.3-second 0-62 mph sprint time and a 146 mph top speed. Combined fuel economy is 50.4 mpg, equivalent to 129 grams of CO2 per km.
The diesel contingent is initially represented by the latest 2.0-litre TDI producing 150 PS and 320 Nm (236.02 lb-ft) of torque. It powers the A3 Saloon from 0 to 62 mph in 8.7 seconds, takes it to a top speed of 137 mph and is capable of returning up to 68.9 mpg. This equates to CO2 output of 107 grams per km.
At launch in the UK, 2.0-litre TDI versions are paired with a six-speed manual transmission, and 1.4 TFSI and 1.8 TFSI options with the S tronic dual-clutch gearbox, which shifts without any noticeable break in propulsive power, and is controlled by either the selector lever or paddles on the steering wheel. S tronic offers a free-wheeling function in its efficiency mode which further reduces fuel consumption. More engines, additional engine and transmission permutations and models equipped with quattro permanent all-wheel-drive will come on stream during 2013 and beyond.