IT'S all about the numbers game for Audi as it launches its latest range of mid-sized, premium saloons and estate cars.

The German brand's petrol and diesel-powered, mid-range executive models have carried the A4 designation since they were first launched some 30 years ago, but no more - now they have morphed into the A5.

With the expansion of its model range, Audi is restructuring the naming of its vehicles to differentiate between pure electric and internal combustion-engined (ICE) models. From here on in its' electrically powered models will be badged with even numbers and odd numbers will be used for variants with combustion engines.

Confusingly, perhaps, the ICE-powered A5 - which will come in saloon and Avant body styles and with petrol and diesel engines - will have some electric power assistance thanks to a new mild hybrid system based on a 48-volt on-board electrical system which supports the combustion engine and reduces CO emissions while increasing performance.

As well as getting an extra digit, the new models are growing in length and width. Audi is also expanding the amount of standard and tech equipment, aimed at positioning the new Audi A5 in the upper mid-size segment. Sporting and more dynamic S5 variants of both saloon and estate will be available

There'll be a range of power units available at launch, starting at entry-level with a four-cylinder, 148bhp, turbocharged two-litre petrol engine which is also available with an output of 201bhp. There's also a 201bhp, two litre turbo-diesel. Meanwhile S5 models will come with a powerful three-litre, V6 turbo power plant.

The new A5 range will be launched in Germany and other European mainland countries in November. In the UK, dealers will open their order books in August when full pricing and specifications will also be announced.