Audis Prologue concept shown at LAs auto show last year heralds a "new design language" for the brand

Audi's Prologue concept shown at LA's auto show last year heralds a "new design language" for the brand

Audi will invest EUR24 billion between now and 2020 to expand its production capacity and enlarge its model range from today's total of 50 models to 60. The company sold a record 1.74m cars around the world in 2014 and has high hopes of increasing that again in 2015.

To help achieve that total there will be replacements for at least three Audis this year as well as a huge programme of upgrades for others. An all-new Q7 SUV - weighing up to 400 kilos less than the outgoing model - and a replacement for the R8 supercar will be revealed at Geneva next week, and the next A4 is expected to be the highlight of the company's pavilion at Frankfurt in the autumn.

Audi is also developing a new design language, demonstrated by the Prologue concept car shown at Los Angeles late last year.

Meanwhile, revised versions of the A1, A6, A7 and Q3 are just being rolled out across Europe. There are changes to the interior and exterior styling, improved specifications and new engines which increase power while simultaneously lowering consumption and emissions.

The A1 becomes the first Audi to be powered by a three-cylinder engine - a 1.0-litre TFSI unit which replaces the four-cylinder 1.2 TFSI. It develops an extra 6bhp (a total output of 94bhp) yet has CO2 emissions as low as 97g/km, There are also power upgrades for the two 1.4-litre TFSI engines - one of which shuts down two cylinders when cruising - and the 1.6 TDI diesel, with up to 9% lower emissions.

The 'cylinders on demand' 1.4 also finds its way into the Q3, Audi's small SUV, and there is more power with emissions reductions of up to 17% for the other petrol and diesel engines, including the RS flagship.

It's a similar story with the A6 and A7 ranges. Here, the emissions reductions are as much as 22% in some cases. Even the already frugal and relatively new ultra models - aimed squarely at business users -­ benefit. The A6 ultras now have glassfibre reinforced polymer springs 40% lighter than the previous steel springs, while an S-tronic automatic gearbox replaces the continuously variable transmission in front-drive versions and includes a coasting function to save fuel.

In the UK, Audi is celebrating 50 years as an importer in 2015. Cumulative sales recently topped two million, having doubled in the past decade, and the 2014 total of almost 159,000 was a record in the British market.