New Audi A3 Sportback and saloon go on sale from £22,410

The mild-hybrid A3 uses a belt-driven starter-alternator to feed a 48V system that can recuperate 16bhp during deceleration and gentle braking. It can also glide with its engine off for up to 40 seconds. There are no official plans to add this tech to other engines in the A3, but powertrain engineer Michael Vogl said that it could be integrated into almost any powertrain.

“This system helps us to achieve our goals and helps our customers to save fuel,” said Vogl. “There are low cost increases and low weight increases but an improvement of 10% in consumption.”

Following the first wave of engines, further TDI and TFSI options will arrive, including some with Audi’s quattro four-wheel drive system.

The flagship Audi S3 and Audi RS3 performance models will be launched later this year. The former, which we have already driven in prototype form, delivers 306bhp from Volkswagen’s 2.0-litre four-cylinder turbo engine, while the latter will continue with its trademark five-cylinder unit, as found in the new Audi RS Q3.

For those familiar with the A3, the interior is most noticeably changed. Audi has taken the controversial but increasingly popular route of minimising physical controls, ditching the rotary controller for the infotainment system on the centre console.

A new shifter for the dual-clutch automatic gearbox sits in a black gloss surround, close to a round, sensory volume controller that reacts to circular finger movements.

There’s a 10.25in digital instrument display and a 10.1in infotainment touchscreen angled slightly towards the driver, while a new climate control unit below it replaces rotary dials with buttons.

The A3’s electronics project manager, Melanie Limmer, said the decision to remove some physical buttons was made as “more and more people are getting into touch functions with smartphones” and claimed that the new system is as user-friendly as the previous one.

Digital features include up to six user profiles, a wi-fi hotspot, handwriting recognition and improved natural voice control. For example, ask “Where’s the nearest Italian restaurant?” and the sat-nav system will show those nearby.

As well as Apple CarPlay and Android Auto, Amazon’s Alexa voice assistant will become available by this summer.

Audi promises that the new A3 offers better comfort and dynamic properties than its predecessor in all of its forms, but particularly when aided by optional adaptive damper control, progressive steering and four driving modes.

Its MQB II architecture, which it shares with the new, eighth-generation Volkswagen Golf, is claimed to be lighter yet also more rigid than the platform it replaces.

The five-door hatchback and four-door saloon won’t be the only A3 bodystyles to hit showrooms. The absence of the three-door hatchback means no A3 Cabriolet will be produced this time, but Audi plans to introduce a high-riding A3 Allroad model in its absence, with crossover-like styling and a chassis tuned around all-season tyres. This is set to challenge the new Mercedes-Benz GLA from the end of 2021.

Autocar understands that there are also plans for a Mercedes-Benz CLA-rivalling five-door liftback, which is expected to arrive next year.

Q&A: Juan Carlos Huerta Martinez, A3 exterior designer

What was your goal with the new A3?

“We had a clear goal with this generation: we wanted to bring more typical hot hatch properties. The proportions are much sportier than in the previous generation and the roof line is lower, more dynamic. We don’t have the sporty three-door A3 now, so it was important to bring sportiness to the Sportback.”

What was your inspiration for the new A3?