Background
You might not expect the most aerodynamic combustion model Audi has ever made to be a big A6 Avant estate, this six generation C9-series model. But perhaps you should. Slippery bodywork has always been a calling card of this model line. The very first C4-series version of 1994 was a re-badged version of the most slippery big car of the '80s and '90s, the Audi 100. And the first bespoke design with an A6 badge, the C5-series model of 1997, set another new standard for how slippery a big estate could be.
It's successors, the C6 design of 2004, the C7 model of 2011 and this current car's predecessor, the C8 design of 2018, continued the trend of form over function. Customers could fit much more in a rival Mercedes E-Class Estate, but the A6 Avant always vastly out-sold that model in our market, whilst also trumping the other big segment player, BMW's 5 Series Touring.
This C9-generation model, announced in early 2025, was originally supposed to switch to 'A7' badging so as not to cause confusion with the all-electric A6 Avant e-tron launched in 2024. But a last-minute change of policy by Audi saw this combustion model keep the 'A6' moniker. It's still offered in diesel form as well as in petrol guise - it'll actually be one of the last diesel models Audi will ever launch. And there's a saloon version too. But here our focus is on the Avant.
Engines and Tech Spec
In a market where rivals are starting to wonder whether they should have been quite so hasty in dropping diesel power, this A6 Avant celebrates the black pump, reserving arguably its most sophisticated engine tech for the TDI version, which uses the company's usual four cylinder 2.0-litre unit. As with the A5 Avant, this means installation of the brand's MHEV plus system, which offers a big step forward from Ingolstadt's previous mild hybrid technology. For one thing, it uses a much bigger e-motor, providing 24PS and 230Nm of torque. For another, it acts as more than just a starter generator, also able to drive the car on its own at parking speeds. Plus, using a brake-by-wire set-up, the system can also regenerate energy at up to 25kW, so the compact lithium battery will always be topped up.
As we said, the 2.0 TDI unit in question is a familiar one - and the quattro 4WD system it must be paired with is familiar too. Total output is 204PS, which is the same as the alternative four cylinder engine on offer, the 2.0 TFSI petrol. This can only be front-driven and makes 62mph in 8.3s en route to 144mph, respectively 1.3s and 5mph slower than the diesel. The UK won't get the 3.0 V6 TFSI petrol unit offered on the continent. But we will in future see a range of Plug-in Hybrid TFSI e powertrains, including those likely to be used in the future high performance S6 and RS 6 models.
Audi claims drive dynamics have been improved with this C9-generation design. To that end, there's a stiffer torsion bar, stiffer control arm bushings, a more rigid steering rack and increased front camber. All of this is supposed to improve steering feel and road feedback. Plus the sleeker bodywork should help refinement.
Design and Build
This is by far the most dynamic-looking A6 Avant there's ever been. With its lower roof line and pumped-up wheel arches, even an entry-level variant appears to have an S6-vibe. Aerodynamics have been prioritised over practicality, resulting in a low drag coefficient of just 0.25Cd. So it's just as well that the 4,990mm body length is a full 60mm longer than the previous C8-series model.
The front end borrows cues from the A6 e-tron and the e-tron GT, with the familiar Audi rings moved from the enormous grille up to the bonnet and the headlights placed higher and wider across the new nose. The sculpted rear has a striking light bar that sits below bright brake lights with OLED panels. Wheel sizes are between 18 and 21-inches.
Inside, Audi serves up most premium-feeling cabin in the segment, its architecture similar to recent models like the A6 e-tron, the Q6 e-tron and the Q5 (all developed at much the same time). Which means a huge central fascia panel called the 'digital stage' that houses an 11-inch instrument screen and a 14.5-inch central infotainment monitor in a single curved housing. There's no lower centre stack screen as in the old model, but customers can specify an optional 10.9-inch passenger side display.
As long as you don't mind shiny black trimming, you should feel it to be all quite high-end, with high quality soft-touch finishes and leather-like materials wherever you look. There are some nice tech touches, like the optional 'dynamic' sunroof which can be switched between translucent and clear - and also has an interim slatted 'pergola' mode. We're pleased to see the retention of some proper physical controls around the dashboard too.
Rear seat space is impressive; even a lanky passenger stuck behind a tall driver will have plenty of leg room. And the swept-back roof line doesn't seem to compromise head space too much. It has though, affected boot space, which once the kick-operated tailgate rises is revealed as 503-litres (down from 565-litres in the old car). That figure rises to 1,534-litres with the rear seats down. These are the smallest-capacity figures in the class, but Audi thinks they'll be quite sufficient for the target market. Thanks to its width of 1,050mm, this is at least a practical space - two large suitcases can fit in side by side. The standard 40:20:40 folding rear seats enable variable loading for items such as ski equipment. A rail system and a partition net come included.
Market and Model
Let's get to the pricing, pitched from launch from £52,510. There are the usual 'Sport', 'S line' and 'Edition 1' trim levels. Opt for mid-range 'S line' trim (as most customers will) and you'll be offered the change to find an extra £2,650 to get Audi's optional 'Sound and Vision Pack'. This includes a head-up display, headrest speakers, increased charging capacity for the USB ports and a Bang & Olufsen premium sound system with 3D sound. The pack also includes Audi's 'ambient lighting package pro' set-up, which means you get the useful 'dynamic interaction light' which arches around the top of the dash and illuminates in different colours to warn you of safety issues, drive mode selections or 'phone settings. Many customers will also want to pay extra for the optional 'dynamic' panoramic sunroof.
Matrix LED headlights come as standard - with a choice of seven digital light signatures for the daytime running lights at the front. Alloy wheel rim sizes range from 18 to 21 inches across the range. The central screen has the latest version of the "Hey Audi" voice-activated Audi assistant, which puts you on speaking terms with numerous vehicle and infotainment functions, from adjusting heating to weather information. And you can control a lot of these features remotely via the my Audi app. 'S line' models get sport exterior touches. And a few well-chosen sporty cabin embellishments, including branded contoured front sports seats. All the usual camera driver assistance safety systems you'd expect are of course included.
Cost of Ownership
Expect around 45mpg on the combined cycle and around 140g/.km of CO2 from the TDI diesel; obviously, you'll do a little worse than that with the 2.0 TFSI petrol version. The key engineering efficiency development with this new A6 Avant is, as we told you in our 'Driving' section, the new 'MHEV plus' mild hybrid system that features on the diesel versions. This is based on a 48-volt on-board electrical system that supports the combustion engine and reduces CO2 emissions while increasing performance. Its added powertrain generator (the 'PTG') enables electric driving components that contribute to a reduction in fuel consumption.
The 'MHEV plus' system offers advantages in CO2 emissions compared to the previous MHEV set-up. Over the WLTP driving cycle, these total up to 10g/km of CO2 in the 2.0 TDI. The PTG can also add up to 24PS of electric power to the output of the combustion engine. When decelerating, the PTG feeds energy back into the battery at up to 25kW. As a result, purely electric manoeuvring and parking are possible to a limited extent.
Thanks to the option of using an electric air conditioning compressor, the air conditioning system can also be operated when the vehicle is stopped at traffic lights and the combustion engine is switched off. With the integrated and blending-capable brake control system, the brake pedal and the brake hydraulics can be completely decoupled. In models with the 'MHEV plus' system, it achieves the necessary deceleration without using the friction brakes thanks to regenerative braking. This means that deceleration is initially achieved solely by recuperation. The friction brakes only kick in when the brake pedal is pressed harder. The brake feel remains unaffected by this.