Audi has upgraded the battery used in plug-in hybrid (PHEV) versions of the A6, A7 and Q5, giving a greater zero-emission range.

The lithium-ion battery now has a gross capacity of 17.9kWh with a voltage of 381 volts.

PHEV powertrains are also now offered in the Q5 Sportback and the A6 Avant, for the first time.

The A6 TFSI e saloon models can now cover up to 43 zero-emission miles, while the A7 has a 42-mile range.

A new A6 TFSI e Avant model launches with a 41-mile zero-emission range.

Following the improvements, the BIK tax rate for the majority of A6 50 TFSI e quattro Saloon models decreases from 11% to 7% (2021/22), and this rate also applies to Sport and S line versions of the new A6 Avant 50 TFSI e quattro. Sport, S line and Black Edition versions of the upgraded A7 Sportback also fall into this category.

Andrew Doyle, director of Audi UK, said: “The significant increases in electric-only driving range made possible by the improved battery in these newcomers will bolster their environmental integrity and financial viability, particularly in terms of BIK taxation for business users, and the same will of course apply to the fleet-oriented A6 and A7 models that have also benefited from the upgrade.”

Like the other models, the new Q5 Sportback is offered with two power outputs: the 299PS 50 TFSI e and the 367PS 55 TFSI e. It provides a zero-emission range of up to 37 miles.

Both are capable of returning economy figures ranging from 141.2mpg to 156.9mpg, which equates to CO2 output of between 42 and 45g/km.