SMOOTH, sleek, efficient and classy - all words that aptly describe Audi's popular executive saloon, the A6.

This is one of those cars that's continued to evolve, both in terms of its cutting edge technology and go-to image during the 27 years it has been around.

And with electricity at the forefront of car manufacturers' plans, the latest offering from the A6 stable could prove irresistible to private drivers and business users alike.

It is the A6 50 TFSI e plug-in hybrid which combines a 2.0-litre turbocharged petrol engine with a 14.1kWh electric battery to develop a hefty output of 299PS with 450Nm of pulling power.

But equally impressive are the Audi's green credentials - the ability to drive up to 34 miles in zero emission electric-only mode plus overall CO2 emissions of 35g/km.

The upshot is that this eco-friendly performance means a low benefit-in-kind tax rate of as little as 10 per cent.

Performance is predictably smart, the A6 capable of blasting from 0-62 in 6.2 seconds and on to a potential top speed of 155mph. Even in pure electric mode you can touch 84mph.

And Audi insists that providing the hybrid is plugged in regularly it can return a whopping 188 miles per gallon.

With a bit less discipline - and more infrequent charging - like in my case, then we're talking appreciably less.

Charging, meanwhile, takes two and a half hours via a domestic wallbox or at a public charge point and by downloading the myAudi app you can preset for the cheaper off-peak electricity supply times.

It's also a treat to jump into a warm, defrosted car on cold mornings, and the app can also activate and adjust the climate control. With the arrival of summer you can cool things down in advance.

As for the driving experience well it comes as no surprise to find the A6 a joy - swift, beautifully balanced and relaxing, while sound intrusion is virtually non-existent.

Transmission is via a seven-speed S tronic gearbox that shifts sweetly in auto mode and can be operated using the steering wheel-mounted paddles if desired.

Drivers can also pick between a trio of drive modes - EV for completely electric driving, Hybrid which combines the petrol and electric motors plus a Hold setting to conserve the electrical energy.

And there are separate drive modes called Efficiency, Comfort, Auto, Individual and Dynamic, operated at the push of a button.

Four trim grades comprise the A6 hybrid line-up - Sport, S Line, Black Edition and Vorsprung - and all come with Audi's all-digital MMI Touch Response set-up featuring two touchscreens with voice control.

Kit includes full smartphone connectivity via Android Auto or Apple CarPlay, a wireless charging pad and Amazon's cloud-based Alexa function for streaming music or audiobooks.

Cabin space is plentiful, both front and back, and the long boot can cope with substantial loads while inside the effect is best described as minimal with lots of brushed aluminium, piano black and premium leather.

Standard kit is comprehensive, the likes of 18-inch alloys, front and rear LED lamps and electronic driver assistants including the Audi Parking System Plus, Pre-sense Front collision warning and automatic braking system along with a Lane Departure Warning all included.

And such is the A6's attention to detail that even the lens of the rear view parking camera can be kept clean with its own water jet.