2021 (71) Audi A6 50 TFSI e 17.9kWh Quattro Sport 4dr S Tronic

By Jonathan Crouch

Introduction

Back in 2020, Audi announced its intention to play a key part in the plug-in part of the full-Executive saloon segment with this frugal A6 50 TFSI e model. If you can afford the significant PHEV price premium over an ordinary combustion C8-era A6 from this period, the other downsides aren't too great. From a very cool, classy Audi.

History

If you're thinking of a full-sized Executive segment saloon, you have to consider the option of Plug-in hybrid technology these days - the potential Benefit-in-Kind taxation savings are just too good to ignore. Which back in 2020 made Audi's A6 50 TFSI e model significant. Unlike other larger Audi plug-ins from this era, it used four cylinder rather than six cylinder power. But in the used market for the right kind of customer, its figures might represent a compulsive argument against the diesel alternative. All 50 TFSI e models came with quattro 4WD. This C8-era A6 PHEV model was initially launched only in saloon form, but in 2021 an Avant estate variant followed; and in 2023 (along with a light facelift), Audi introduced a slightly larger battery for this model with longer EV range. When the new C9-era A6 arrived in early 2025, the Plug-in Hybrid variants got 'e-Hybrid' badging.

What You Get

There are few visual giveaways as to this TFSI e model's plug-in status - unless you're eagle-eyed enough to spot the altered badgework and the extra charging flap. So, as usual with a fifth generation A6, there are taut surfaces, sharp edges and striking lines, plus a long bonnet, a long wheelbase and short overhangs. At launch in 2020, this PHEV A6 model was only offered in this saloon form, but an Avant estate version followed shortly after. The interior is of course virtually identical to a conventional C8-era A6 model. Up front, the dash features the black-panel design we first saw on the larger D5-era A8. You're going to need to like screens because this car's classy interior can incorporate no fewer than three of them, the two you'll notice first powering up as soon as the door is opened and dominating the upper and lower parts of the piano black-trimmed centre stack. Legroom in the rear exceeds the space you'll get in core competitors, while headroom and shoulder room measurements in both front and rear are also generous. Not so good was the way the PHEV tech reduced boot space - from 530-litres to just 360-litres in the saloon, thanks to the battery pack that must sit under the cargo area floor. It's 405-litres in the Avant. So you're going to need the split-folding rear bench.

What to Look For

Not too much goes wrong with a C8-era A6 of this sort. The most common issue we've heard of relates to excessive oil consumption for models with this PHEV model's 2.0 TFSI petrol engine. The most reported C8-era A6 faults relate to interior trim and non-engine electricals. We've had some reports of issues with wear to the side bolsters of the leather seats, as well as squeaking front brake pads, so it's worth looking out for both of those. There were a few issues with the car's infotainment system, with phones not connecting properly and flickering screens being the main problem. The DSG automatic gearbox should be checked to make sure it's had a regular oil and filter change, as should the quattro four-wheel-drive system. Many A6 models will have been company or lease cars and, as a result, you should check the condition of the bodywork carefully. The high-quality fit and finish of an A6 also makes it an ideal candidate for clocking, so ensure the history is absolutely verified. If the A6 you're looking at has a panoramic glass roof and was an early C8-era model, be aware that on a few cars, this roof became unstuck from its frame.

Replacement Parts

(approx based on an A6 50 TFSI e (2020) - Ex Vat) An air filter costs in the £84 bracket. An oil filter costs around £6. A fuel filter is around £27. Front brake pads sit in the £58 to £91 bracket for a set; for a rear set, it's around £25. Front brake discs sit in the £51 bracket; for a rear pair, you're looking at around £77-£186. A headlamp is in the £968-£1,170 bracket; and a wiper blade is in the £11-£19 bracket.

On the Road

Back in 2020, Audi's TFSI e plug-in technology came in a variety of forms. In this C8-era A6, it was based around the brand's usual four cylinder 2.0 TFSI petrol engine, to which was added an electric motor integrated into the auto gearbox. In earlier models, that motor was powered by a 14.1kWh lithium-ion battery pack (a larger pack was added in 2023). When fully charged, the 14.1kWh pack will allow the car to run in all-electric motion for up to 34 miles (WLTP-rated). There's a total system output of 299PS and 62mph from rest takes just 5.5s. In all-electric mode, the car can cruise at up to 84mph - or up to 152mph with the engine in use. Pleasingly, in usual motoring, Audi engineered the combustion powerplant only to fire up when you really flex your right foot (or obviously when the battery's low on charge). That's particularly the case if you run the car in its provided 'EV' mode which keeps you in electrified motion for as long as possible. More usually, you'll be driving in the 'Auto' setting, which mixes use of petrol and electric power and can be set in a 'Hold' form where the battery saves its charge for urban driving you might have to do at the end of a longer journey. Not particularly good is the response of the dual-clutch 7-speed S tronic auto gearbox which could switch between its ratios a little more smoothly. You might also notice a slightly firmer ride than would be the case in a conventional A6 - blame the extra weight of the hybrid system, which has necessitated firmer springs. Despite the stiffer damping, this front-driven Audi can't match a rear-driven plug-in BMW 5 Series or Mercedes E-Class from this era for driver involvement, but points are regained by something typical executives will value more - low noise levels. There's a barely noticeable shiver when the petrol engine fires up to replace battery power on the move and refinement's excellent, even when you are using fossil fuel. And quattro 4WD is standard. As with any C8-era A6, highway cruising is impressively silent. And it's for this kind of driving that Audi offered the option of building in a package of so-called 'Level 3' autonomous driving tech. The 'Traffic Jam Pilot' system original buyers could specify on this car only allowed that facility on properly divided major roads at speeds of under 37mph but in operation, it was undeniably impressive. As were the associated 'Parking Pilot' and 'Garage Pilot' systems that allowed A6 owners to remotely park their cars when they reached your destination. As with any PHEV, to get the most out of this A6, you'll need to keep the car charged up (which should take around two and a half hours from a 7.2kW garage wallbox) and make the absolute most of the potential all-electric driving range, rated at about 34 miles. If you don't do that, you'll essentially end up with a heavier version of the conventional 45 TFSI petrol variant - and take it from us, one of those isn't going to be cheap to run. This 50 TFSI e derivative, in contrast, very much is. Let's get to the WLTP-rated figures. For earlier 14.1kWh versions, the combined cycle fuel economy is rated at between 166.2 and 188.3mpg and the CO2 emissions reading is 35-39g/km. In its earlier forms, this executive saloon's lithium-ion battery is made up of 104 prismatic cells and stores 14.1kWh of energy with a voltage of 381 volts. And the car was supplied as standard with a compact charging system plus a Mode 3 cable with Type 2 plug for use at public charging stations. The charging system features an LED status display and safety functions such as temperature and residual current monitoring. The integrated charger replenishes the lithium-ion battery with a maximum power of 7.4kW. Even from a 220V household three-pin plug, an empty battery can be fully and conveniently recharged overnight in roughly six hours.

Overall

By 2020, we'd seen plenty of Audi PHEV hybrid models, but this was a more credible one. To be frank, it doesn't really offer much you can't also get from rivals sold by BMW and Mercedes from this era. But it doesn't lack much that these competitors offer. Which means that if you are attracted by this A6's effortlessly cool vibe, classy cabin and uber-smooth refinement - as plenty in this segment are - then there are a few reasons not to sign your cheque Ingolstadt's way. An early 50 TFSI e has drive range that looks embarrassingly small by current segment standards. And offers a rather compromised luggage compartment compared to a more conventional C8-era A6. Still, for the right money, one of these could still make all kinds of sense.