Used Audi A6 2018-2025 review

Steady evolution has always been the name of the Audi A6’s game, almost back to the very olden days when it was known as the Audi 100. This process of natural selection is not to be feared, however, because the A6, whether in saloon guise as here or as the more voluminous A6 Avant estate version, has in recent years developed into rather a splendid car.

This latest version, launched in 2018, ups the ante even further, even if at first glance it looks rather similar to the 2011-2018 Audi A6 model it replaced. Underneath, it harnessed new technologies borrowed from other Audis, cars such as the A7 Sportback and the expensive Audi A8, in the hopes of making this luxury car more comfortable, more efficient and more desirable. Chief among these are an aluminium chassis and some mild hybridisation for each variant.

Engines and performance: The petrols are a turbocharged 2.0-litre four-cylinder unit, in either 4o or 45 TFSI guise, or a twin-turbocharged 3.0-litre V6 in the range-topping 55 TFSI. The diesel options start with a 204bhp 2.0-litre 40 TDI four and finish with a 280bhp 3.0 V6 50 TDI. A lower-powered 3.0-litre diesel, badged 45 TDI, was launched a couple of years in. All are four-wheel-drive quattro models, except the base 2.0 TDI, which can be had as a front-wheel-drive car only. The later 50 TFSIe plug-in hybrid comes with a range of up to 34 miles, according to official figures.

The mild hybridisation comes in a 48-volt system for the six-cylinder engines and a 12-volt one for the four-cylinder unit. The idea is that a belt alternator/starter connected to the crank recovers energy under deceleration and stores it in a lithium-ion battery under the boot. The A6 can also coast with the engine idling at speeds between 34 and 99mph, and the stop-start function can operate at higher speeds too, all in the name of fuel efficiency.

On the road, it’s mightily impressive. The 2.0 diesel can feel a little lethargic, but the rest of the engine options don’t lack for punch. Only a lag in the transmissions can annoy, as there’s often a slight hesitation between putting your foot down and anything actually happening. The 3.0 petrol V6 cars are both flyers, but their fuel consumption is commensurately high.

The 50 TFSIe plug-in hybrid responds the most enthusiastically when you ask for a burst of acceleration because of the plentiful electrical assistance. Even when you're running in fully electric mode its petrol engine springs into life quite quickly to help out, and the 0-62mph time of 6.2sec is plenty fast enough.

All the engines are hushed, mind you, including the four-cylinder diesel. Wind and road noise are low, too, and the interior of an A6 is generally a calming place to be.

Ride and handling: There were four suspension options to choose from when the car was new. Entry-level Sport trim uses conventional steel springs and dampers, S line models use the same, but stiffened and lowered, and there was the option of adaptive suspension that comes with switchable dampers that can be softened or stiffened to suit your mood. We’d recommend you seek out a car with this fitted, if possible. Adaptive air suspension was an even pricier option, but shop around and you may pick up a car with it on, although oddly it can be caught out by sharp bumps taken quickly, causing a most unseemly thud.

Approach a corner and the A6 feels lighter and more agile than its size would lead you to believe. Some cars even come with four-wheel steering, which makes things sharper still. There’s plenty of grip and the overall balance instils confidence in the driver, even if one or two of its luxury-car rivals are more precise.

Interior and practicality: Inside, it’s easy to find the right driving position, thanks to an electrically adjustable seat and steering wheel. The driver is definitely pampered, with lumbar support and a dashboard of unimpeachable logic and good-quality materials. As standard, you get clear analogue dials ahead of you, but if the Technology Pack has been added these are replaced by digital dials on a 12.3in screen. They're excellent, doing more than analogue dials by being highly configurable and showing a wealth of useful information just below your sightline. There’s also the option of a head-up display.

Visibility is excellent, with front and rear parking sensors and a rear-view parking camera. Unfortunately, this generation of Audi’s infotainment system swapped a rotary controller (like BMW’s iDrive) for a touchscreen with haptic feedback, which wasn't as good as the previous set-up. The screen is sharp and, as standard, it's 8.8in diagonally across, but if you find a car with the Technology Pack fitted, the upgrades include a larger 10.1in screen.

Up front, there’s plenty of space for two, while in the rear passengers enjoy more leg and head room than most rival cars offer. A central third passenger will have to straddle a small central tunnel but otherwise gets a good amount of room. The boot is positively massive, and is a good shape and easily accessible - it’s one of the best in its class.

Trims and equipment: Standard equipment is pretty generous on any A6. All models come with electric front seats and LED headlights, and the entry-level Sport also comes with 18in alloy wheels, leather seat trim, dual-zone climate control, ambient LED interior lighting and keyless go. Upgrade to S line and you’ll get bigger 19in wheels and firmer sports suspension and adaptive LED headlights, as well as a lot of styling add-ons.

"Audi was at the top of its game for interior quality when this A6 was launched. I actually find this car more luxurious than its successor." – George Hill, Used Cars Writer

If you're interested in finding a used Audi A6, or any of the other cars mentioned here, head over to the Used Car Buying pages to find lots of cars listed for sale at a great price.

You can find a used A6 of 2018 vintage for between £12,000 and £14,000, usually with very high mileage. Spend between £14,000 and £17,000 on a 2018, 2019 or 2020 model with lower miles. Expect to spend upwards of £18,000 on a 2021 or 2022 model and above £20,000 for a 2023 car. Later 2024 and 2025 models start from around £30,000.

MPG

Thanks to its hybrid technology, the CO2 emissions are sensible and its average fuel consumption is respectable, too. The 40 TDI puts out just 117g/km, and when we tested the economy we managed an average of 46.8mpg; both figures are better than its main rivals the BMW 520d and the Mercedes E 220 d can manage. The V6 diesel is reasonably economical too, considering its performance, but the V6 petrols are both thirsty old Hectors. Officially, the 40 TFSI averages 39.8mpg, the 40 TDI 50.4mpg, the 45 TFSI quattro 37.2mpg, and the 50 TFSIe hybrid 235.4mpg.

Road tax

All examples of this generation of A6 were registered after April 2017 so attract a flat-rate fee, currently £195 a year, plus an additional cost for cars that cost more than £40,000 when new, currently £425 a year. This is payable from years two to six. To find out more about the current road tax costs, click here.

Servicing

Examples that are over three years old will qualify for Audi’s fixed-price servicing, which costs from £185 for a minor service and £355 for a major one, based on cars with a 2.0-litre engine. A6s with larger engines will cost £215 and £409 for the same level of work.

Insurance groups

Insurance groups for the A6 are slightly higher than the equivalent models from BMW and Mercedes, with 2.0-litre diesels starting in group 33; the more powerful 3.0-litre BiTDI in group 44, followed by the most potent RS6 in group 50.

Reliability

According to owner responses in our latest What Car? Reliability Survey, the Audi A6 is a dependable long-distance cruiser, but it's increasingly prone to electrical glitches and mechanical issues (like high oil consumption or water pump failure). These faults can lead to expensive repair bills, so a full service history is essential to ensure you're buying a well-maintained example.

To get the full picture of how this executive model performs over time, head over to our dedicated used Audi A6 reliability page.

Engine

The 2.0 TDI four-cylinder diesel is an engine that imbues the A6 with remarkable refinement, such that there are times you wouldn’t know it was a diesel. It’s the cheapest in the range and is also the most economical and, unless you are more interested in straight-line speed, that’s enough to make it the one we’d seek out.

Trim

Likewise, we’d stick with Sport trim as this offers all the goodies you could reasonably want or need.

Our favourite Audi A6: 2.0 TDI Sport

The BMW 5 Series has long been the benchmark saloon in this class. It’s plush enough inside to compare with just about any other car on sale. It has a spacious, well-appointed interior and it’s great to drive, with a refined and economical range of engines.

The Mercedes-Benz E-Class has a range of smooth and strong engines, a supple ride and a generous amount of standard equipment. It’s good to drive, if not up to the 5 Series’ exceptional level.

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If you're interested in finding a used A6, or any of the other cars mentioned here, head over to the Used Car Buying pages to find lots of cars listed for sale at a great price.