AUDI is adding a plug-in hybrid to its new-look A6 line up of saloon and estates.

The new A6 Saloon and Avant e-hybrid quattro models build on the strengths of their TFSI e predecessors, and will be available in the UK with a 299ps drivetrain delivering which has an electric-only driving range of up to 64 miles.

Both variants are set to go on sale in early June with Sport, S line and Edition 1 specification options priced from £60,980, and customer deliveries will begin later in the summer.

The new Audi A6 Saloon and Avant e-hybrid quattro modelsare powered by a 2.0 TFSI engine with an output of 252ps and an electric motor that delivers up to 105 kW.

With a total system output of 299ps UK specification versions can accelerate from 0 to 62mph in 6.0 seconds and, where conditions allow, reach a top speed of 155mph.

Emmisions are as low as 48g/km with an official fuel economy of 134.5mpg.

The heart of the plug-in-hybrid technology is the high-voltage battery, the capacity of which has been boosted to 25.9 kWh, a gain of around 45 perent compared with previous generations.

This enhancement ensures that, depending on version, the saloon can travel for up to 64 miles under electric power alone, and the Avant for up to 63 miles.

Maximum AC charging power is now 11 kW, and if the battery is completely empty, a full recharge to 100 per cent can take 2.5 hours.

Recuperation performance has also been improved. The degree of recuperation intensity in electric driving mode can be adjusted to three different levels using paddles on the steering wheel.

The vehicle recovers energy automatically when this function is activated. This is based on route data stored in the navigation system. The new A6 e-hybrid quattro can also recover energy automatically without active route guidance.

Two operating modes are available: EV and hybrid. In EV mode, the plug-in hybrid models run solely on electric power, while in hybrid mode, the hybrid management system maintains a specific charge level as needed in order to save enough electrical energy for later use.

In addition to the automatic hybrid mode, the desired charge level can be individually selected using a digital slider.

Suppression of noise in the cabin has been improved by up to 30 per cent compared with the previous model, thanks to detail enhancements such as more tightly sealed windows and optimised door seals.

In EV mode, the PHEV models run on electric power. The combustion engine is only turned on in the following situations: when EV mode is deliberately deselected in the switch bar below the panoramic display or via the MMI; in driving program S; via the selected mode of the Audi drive select dynamic handling system; or when starting route guidance with hybrid assist activated.

If navigation route guidance is activated, the hybrid assistant takes the route data into account when selecting the drive mode.

The six model range will top out from £70,630 for a A6 Avant e-hybrid quattro Edition 1.