Audi A6 vs. BMW řady 5: Complete comparison 2026

Audi A6 represents the embodiment of an elegant and technologically advanced executive car, renowned for its first-class interior craftsmanship and the ultimate confidence of its premium all-wheel drive. On the other hand stands the BMW 5 Series, a legendary representative of the executive class, which has long maintained its reputation as the benchmark for dynamics, primarily thanks to its sporty character and precise handling. In the following comparison, we will therefore focus in detail on the strengths and weaknesses of these two iconic German rivals and find out which of them currently represents the smarter choice on the used car market.

When choosing an executive car approximately four years old, you will most often encounter the Audi A6 (C8) and BMW 5 Series (G30/G31) generations on the used car market. Both cars proudly represent the executive class, which in practice means their total length is dangerously close to the five-meter mark. In this regard, the BMW 5 Series is slightly longer – its body measures up to 4,963 mm in length, while the Audi A6 ends at 4,939 mm. Although the 24 mm difference is small on paper, the overall length of both cars means that when parking in cramped city garages, you will have to rely fully on parking cameras and assistance systems.

If we focus on width and height, each automaker has chosen a slightly different approach. The Audi A6, at 1,886 mm, is 18 mm wider than its Munich competitor (1,868 mm). This slight lead gives the Ingolstadt representative a visually wider and more stable stance, which is positively reflected in the interior with a better sense of airiness and shoulder room. Conversely, the BMW 5 Series builds its silhouette slightly higher. Especially in the estate version (Touring), it reaches a height of 1,498 mm, which is just under 3 centimeters more than the Audi A6 Avant (up to 1,467 mm). The higher build of the BMW can thus slightly facilitate entry and theoretically provide more generous headroom for passengers.

From the perspective of interior spaciousness and overall driving comfort, however, the most fundamental parameter is the wheelbase. In this discipline, the BMW 5 Series, with a value of 2,975 mm, clearly has the upper hand over the Audi A6, which offers 2,924 mm. This more than five-centimeter difference (exactly 51 mm) plays into the hands of BMW, which thanks to it can offer more legroom for rear passengers and at the same time slightly more confident directional stability during fast highway travel. The shorter wheelbase of the Audi, on the other hand, gives the car a sense of greater agility and willingness to turn on winding country roads.

When it comes to practicality and everyday usability, luggage capacity plays a key role for many buyers of used executive cars. Whether you are looking for a representative executive sedan or a family estate that can easily handle weekend shopping and longer holidays, both of these German leaders have plenty to offer. In the compared generations (Audi A6 C8 and BMW 5 Series G30/G31), which appear on the used car market as roughly four-year-old vehicles, both models are very close in terms of transport capacity. Nevertheless, there are minor differences that can make your decision easier.

In the sedan body style, both models offer an identical base trunk volume of 530 liters. However, if you opt for the more popular estate variants, the Audi A6 Avant offers 565 liters as standard, which increases to a solid 1,680 liters after folding the rear backrests. The rival BMW 5 Series Touring counters with a very similar value of 560 liters, but slightly leads with a maximum capacity of exactly 1,700 liters when the seats are folded. Both estates thus easily offer enough space for several extra suitcases and can accommodate a stroller or bulkier sports equipment without any problems.

However, potential buyers of plug-in hybrid (PHEV) powertrains must be very careful, as the trunk floor is raised and the volume significantly reduced due to the placement of the traction batteries. This is where the biggest differences in the practicality of both cars appear:

• For the BMW 530e plug-in hybrid sedan, the capacity drops to 410 liters, while the Audi A6 TFSI e fares significantly worse with a value of only 360 liters.
• A similar trend prevails for the more practical estates – the BMW hybrid offers a decent 430 liters (maximum 1,560 l), while the hybrid Audi drops to 405 liters (maximum 1,535 l).

When choosing a second-hand fuel-efficient hybrid, it is therefore necessary to consider whether this noticeable concession in practicality will be sufficient for your daily life.

The ability to tow a heavy trailer plays a surprisingly important role when choosing a premium car. Whether you are considering getting a caravan for family trips, need to transport a boat, or simply require maximum practicality in everyday life, the trailer weight is a key parameter. Both the Audi A6 and the BMW 5 Series represent very capable tow cars in this regard, meeting the most demanding requirements on the market for approximately four-year-old used cars.

If we look at the popular generations for the used car market – namely the Audi A6 (C8 generation, 2018–2025) and the BMW 5 Series (G30/G31 generation, 2017–2024) – we find that both standard and maximum braked trailer values often meet at the same technical maximum.

• Audi A6 (C8): Whether you choose the more economical 40 TDI diesel model or the powerful 55 TFSI petrol six-cylinder, all these engines offer a consistent braked trailer capacity of 2000 kg.
• BMW 5 Series (G30/G31): Traditional conventional engines such as the 530d diesel or the 530i petrol provide the same reliable towing capacity of 2000 kg, making them excellent workhorses even for long distances.

Significant differences only begin to surface when a customer focuses on fuel-efficient plug-in hybrid models, where the weight of the batteries often limits the structural capacity of the rear axle.

While Audi has handled this problem excellently, with even its A6 50 TFSI e or 55 TFSI e hybrid models maintaining an uncompromising maximum of 2000 kg, caution is required with its Munich competitor. Older model years of the BMW 530e plug-in hybrid (2019–2020) show a radically reduced trailer weight of a maximum of 750 kg. For newer 530e versions (2020–2024), the manufacturer has increased the values, yet they range variably between 1700 and 2000 kg.

These differences mean a lot in practice. A full two-ton capacity not only allows for the trouble-free moving of large caravans but, when a smaller trailer is attached, also provides welcome space for several extra suitcases, which is perfectly sufficient for a weekend shop of larger items or a longer holiday with the whole family. Although official specifications in the tables do not list weights for unbraked trailers, cars in this category generally utilize the legislative maximum of 750 kg.

Both the sedans and estates of the upper-middle class easily meet the demands of the vast majority of buyers. However, from a towing vehicle perspective, the Audi A6 (C8) is clearly a "safe bet" because it offers its two tons across almost all versions. While you get comparable power with conventional engines in the BMW 5 Series (G30/G31), when choosing an older plug-in hybrid, it is necessary to carefully check the data in the vehicle registration certificate so that you are not subsequently limited by the tow bar.

Manufacturer data for these models does not generally include specifications for unbraked trailers (legally always limited to 750 kg), so the corresponding column contains no data.

When choosing a premium executive sedan from roughly the last four years (around 2020 to 2022), the engine range for the Audi A6 (C8 generation) and BMW 5 Series (G30/G31 generation) focuses on highly efficient turbocharged units that rely on advanced electrification in the form of mild-hybrid and plug-in hybrid technology. Both manufacturers use turbocharging for their entry-level and top-tier engines, but a fundamental difference lies in the architecture of the larger engines – while BMW relies on its iconic and silky-smooth straight-six, Audi has long preferred the more compact V6 concept (V6 in the 50 TDI or 55 TFSI). For a used car buyer, this means subtle nuances in character and balance. While standard four-cylinder engines like the 40 TDI and 520d focus on unrivaled fuel consumption suitable for fleet high-milers, petrol plug-in hybrids with 50 TFSI e or 530e badges offer an ideal compromise for zero-emission city commuting and plenty of system power for weekend motorway trips. BMW traditionally excels in sportier tuning with the ZF 8-speed Steptronic torque-converter automatic, while Audi counters with its sophisticated quattro all-wheel drive, which in most modern versions relies on the lightning-fast 7-speed S tronic dual-clutch gearbox.

Audi A6 (C8 Generation)

The Audi A6 C8 generation (available from 2018 to the present) covers all the key needs of a modern executive car within its range. Almost all internal combustion models from this generation feature mild-hybrid technology (MHEV), which in practice means imperceptible start-stop operation and the ability to "coast" efficiently with the engine off on the motorway. The core of the diesel offering in used car dealerships consists of the widely available 2.0-litre four-cylinder turbocharged 35 TDI and the popular 40 TDI, which represent an economical choice for motorway cruisers. However, many buyers long for the refinement and dynamics of the 3.0-litre V6 diesel engines labeled 45 TDI and 50 TDI, where Audi uses the reliable 8-speed tiptronic automatic designed for massive torque (up to 620 Nm). Petrol, pure combustion engines are represented by the agile 40 TFSI and 45 TFSI four-cylinders along with the powerful 55 TFSI V6. Powerful plug-in hybrids (PHEV) labeled 50 TFSI e and 55 TFSI e, which combine an electric motor with a 2.0-litre combustion engine, are also appearing more frequently on the four-year-old used car market. From the overview of available model years in the database, it is clear that for the given period of nearly-new cars on the secondary market, the C8 generation versions are pivotal, and although one can come across older models from the C6 or C7 generations (e.g., older 2.0 TDI or 3.0 BiTDI), the table below strictly focuses on used cars roughly four years old, which make the most sense in the current selection from the perspective of value and modern technology.

BMW 5 Series (G30/G31 Generation)

The BMW 5 Series in the G30 (sedan) and G31 (Touring) generation, especially in its facelifted version (LCI) produced until 2024, traditionally emphasizes driving pleasure and offers the occupants an uncompromisingly smooth ride. Unlike Audi's V-configurations, when choosing a six-cylinder here, you get iconic inline power units. A major change during the production of this generation was the widespread introduction of a 48V mild-hybrid system (MHEV) across almost the entire portfolio of combustion engines, which brought an additional 8 kW of power from the starter-generator and lightning-fast responses when pulling away. An enormous sales hit, even on the used car market, is the exceptionally efficient 2.0-litre turbocharged 520d diesel, or the legendary 3.0-litre straight-six 530d, which many owners consider the perfect compromise between brutal power and still very low fuel consumption. Petrol engines start with the agile 520i and 530i four-cylinders, while the highlight of the standard range is the exceptionally characterful 540i version with a turbocharged straight-six petrol engine. For fleet or urban purposes, BMW deployed sophisticated plug-in hybrids (PHEV). The entry-level four-cylinder 530e model helps reduce running costs, but the rarer 545e version combines the possibility of electric driving with a potent straight-six with a system output of 290 kW – you would look for a similar six-cylinder hybrid in the A6 C8 range in vain. All units in the G30/G31 generation are strictly paired with the phenomenal 8-speed Steptronic automatic transmission. Although older engines across generations (such as E60 or F10) and outdated manual gearboxes appeared, for comparison, we have included only variants from the G30/G31 generation in the overview below, which form the backbone of the market for nearly-new four-year-old cars.

Choosing the right engine is crucial for long-term satisfaction with a car. Our recommendations are based on real-world experience, performance comparisons, actual fuel consumption, owner feedback, and long-term mechanical reliability of roughly four-year-old used cars, which represent the most rational choice on the market today. While for Audi, a highly efficient four-cylinder makes the most sense in terms of total costs, for BMW, the legendary inline six-cylinder is the undisputed king of reliability and dynamics.

For the Audi A6, we recommend: 40 TDI (2.0 TDI, 150 kW / 204 hp)

In the C8 generation (available from 2018 to 2024), the two-liter 40 TDI engine is by far the best and safest choice. Although the diesel six-cylinder (50 TDI) might tempt you with higher paper performance and prestige, the four-cylinder is a much smarter bet for a used car in terms of reliability and future service costs.

• Why it's the best choice: It offers an ideal compromise between purchase price, operational efficiency, and sufficient dynamics. Furthermore, it did not suffer from the significant and often criticized software lag of the accelerator pedal that early six-cylinder models of this generation struggled with.
• Technical advantages: The engine produces a very decent torque of 400 Nm, which, in conjunction with the 7-speed dual-clutch S tronic transmission, is more than enough for smooth and brisk driving. A huge advantage is the real-world fuel consumption, which, with a light foot even on the highway, easily stays between 5.5 and 6.5 liters per 100 km.
• Risks and what to watch out for: Since it is a mild-hybrid (MHEV) system, the secondary battery and starter-generator add another layer of electronics. The main mechanical weakness is the condition of the diesel particulate filter (DPF) and oil degradation. If the previous owner subjected the car to short city trips, there is a risk of premature regeneration problems. Before buying, check the DPF fill level with diagnostics and subsequently strictly shorten the oil change interval to a maximum of 15,000 km.
• Who it's for: Ideal for highway mile-munchers, managers, and drivers with a calmer, rational driving style who are looking for premium comfort combined with the running costs of a mid-size car.

For the BMW 5 Series, we recommend: 530d (3.0 I6, 195 kW / 265 hp or 210 kW / 286 hp)

If you are looking for a four-year-old used 5 Series of the G30/G31 generation (produced between 2017 and 2023), it makes no sense to choose anything other than the 530d. The six-cylinder diesel engine with the code designation B57 is an absolute gem, an exceptionally durable piece of engineering, and the benchmark of its class.

• Why it's the best choice: Compared to the two-liter four-cylinders (520d), you get incomparably higher refinement, velvety operation, and a massive power reserve for almost identical fuel consumption. The brilliant pairing of this engine with the 8-speed ZF automatic transmission creates one of the best-functioning drivetrains in the world.
• Technical advantages: Massive torque of 620 Nm (up to 650 Nm for newer mild-hybrids) ensures locomotive-like pull from idle and effortless overtaking at any speed. Real-world fuel consumption for such a massive and fast cruiser commonly stays at a fantastic 6.5 to 7.5 l/100 km.
• Risks and what to watch out for: The basic engine mechanics are literally "bulletproof"; however, the EGR circuit and intake manifold require attention. A typical ailment of modern diesel six-cylinders that spend too much time driving slowly or in traffic jams is carbon buildup in the intake. Before purchasing, it is advisable to have the intake condition professionally checked and, as a preventive measure, use premium additive fuels and occasionally let the car "breathe properly" with more dynamic driving outside the city.
• Who it's for: Experienced drivers, fans of the pure BMW brand character, and travelers. The 530d is the perfect highway express that provides the joy of dynamic driving while letting you step out completely refreshed after a thousand kilometers on the highway.

Official fuel consumption figures often differ significantly from everyday reality. In the laboratory, both premium sedans and estates appear to be fuel-saving miracles, but in normal travel, the weight of both vehicles, any all-wheel drive, and above all, the driver's driving style play a key role. For the most objective comparison of four-year-old used cars, we did not rely solely on the manufacturers' catalog values, but used real data from the crowdsourcing portal Spritmonitor.de, where drivers enter their actual values after refueling over the long term.

We have taken into account the most common engine versions of the generations available on today's used car market – namely the Audi A6 (C8) and BMW 5 Series (G30/G31) with production years around 2020 to 2022. These values reflect much better what actually awaits you at the filling stations.

What do the numbers mean for the average driver?

• Diesel engines still rule the highways: If you are looking for absolute efficiency, the entry-level diesel Audi A6 40 TDI, with an average of 6.2 l/100 km, is an excellent choice for economically minded drivers and highway mile-munchers.
• The six-cylinder miracle from Munich: The BMW 530d demonstrates the masterful level of Munich's engine designers. Although it is a powerful six-cylinder with sovereign dynamics, in the real world, it asks for only 6.9 liters of diesel. It is thus significantly more economical than the comparably powerful six-cylinder Audi A6 50 TDI.
• Gasoline compromises: An interesting, though physically logical, finding is that modern four-cylinder gasoline engines (530i and 45 TFSI) in cars of this size do not save fuel dramatically. Moving nearly two tons of weight simply requires its dose of energy, and real consumption here approaches eight liters.

For typical premium class users who cover tens of thousands of kilometers annually, a modern diesel still makes the most sense. From the perspective of a typical buyer of a nearly new used car, however, consumption is usually not the only deciding factor. For vehicles with a purchase price well over €41,000, a difference of half a liter to one liter per hundred kilometers will not ruin the family budget. Your final choice should therefore depend more on driving characteristic preferences, sympathy for the design of one brand or the other, and the specific equipment of the car.

Buying an approximately four-year-old executive sedan or estate is one of the smartest purchases on the used car market. Both the Audi A6 (C8 generation) and the BMW 5 Series (G30/G31 generation after the facelift) have experienced their steepest drop in value at this age, which for premium brands can exceed 40% in the first few years. Buyers thus get a modern, safe, and technologically advanced car for a fraction of the original purchase price.

Although both vehicles compete very strongly in price when new, slight differences in residual value trends can be observed on the used car market. Everything also depends on the specific engine, body type (in both cases, there is a noticeable surplus of more practical Avant and Touring estates on the market), and the presence of sport packages such as Audi's S line or BMW's M Sport.

The following table shows the average market price range for models with mileage corresponding to an age of 3 to 5 years (typically 80,000 to 140,000 km).

Audi A6: Wide Selection and Excellent Value for Money

On the secondary market, the C8 generation Audi A6 is a highly sought-after car, mainly due to its strong presence in corporate fleets. This creates significant downward pressure on the prices of base models.

• Availability of four-cylinders: The 40 TDI (2.0 diesel) versions with front-wheel drive or the quattro system make up the majority of the offer. These models can be found at very attractive prices, making the Audi a more affordable entry point into the premium segment.
• Six-cylinders and equipment: The 50 TDI models are highly desirable; while the price drop is noticeable, these cars hold their value better. Features like air suspension or superior headlights (HD Matrix LED) reliably push the used car price toward the upper end of the range.

BMW 5 Series: Higher Residual Value Thanks to Its Reputation as a Driver's Car

Over a five-year horizon, the BMW 5 Series (G30/G31) typically loses value slightly more slowly than the Audi. This is due to strong brand loyalty and the extraordinary popularity of its straight-six diesel engines.

• Desirable engines: The 530d and especially the twin-turbocharged 540d models are among the most sought-after executive used cars. Their reputation for combining great dynamics with low fuel consumption ensures higher trade-in and resale prices.
• The M Sport package is essential: On the used market, there is a vast difference between a base trim version (so-called "Luxury Line" or standard) and one equipped with the M Sport package. This package gives the car a more aggressive look and, in terms of resale and value retention, is one of the most important equipment features for which buyers are willing to pay extra.

Both premium models, the Audi A6 and the BMW 5 Series, earned a full five-star rating in their independent Euro NCAP crash tests. When comparing these excellent results, however, it is crucial to consider the context and the specific year of testing. The methodology of Euro NCAP test protocols is constantly evolving and becoming stricter – more demanding frontal impact simulations, tougher tests for cyclist detection, or entirely new emergency braking scenarios at intersections are regularly introduced. For this reason, percentage ratings from different years cannot be taken as directly comparable. Furthermore, for vehicles older than six or seven years, the certification validity usually formally expires, as older models may not fully comply with the latest, much more demanding standards for achieving the maximum number of stars.

The Audi A6 (C8 generation) underwent Euro NCAP testing in 2018 with an exceptionally good result. A rigid body using an intelligent mix of aluminum and high-strength steel ensured the car scored a great 93% for adult occupant protection and 85% for child protection. In the area of vulnerable road user protection, the Audi achieved 81%. Another strength was the overall score of 76% in the safety assist category. The standard Audi pre sense front system significantly contributed to this figure, as it performed very well in detecting pedestrians and cyclists and preventing collisions in urban traffic under the advanced 2018 protocols.

The BMW 5 Series (G30 generation) underwent testing a year earlier, in 2017. Within the standards of that time, it offered a practically identical level of passive safety – 91% for adult occupant protection and 85% for child safety. In the pedestrian protection assessment, the Bavarian model also scored 81%, mainly thanks to the presence of an active hood and effective person collision warning. A more significant deviation appeared in the safety assist category, where the BMW scored 59%. This lower percentage reflects the older assessment methodology and the fact that the five-star rating for 2017 did not account for such widespread implementation of certain more advanced assistants in the standard equipment. It should be added that due to the age of the test, the safety certification for this 2017 model officially expired at the beginning of 2024.

The overall comparison shows that both vehicles provide highly above-average structural integrity for occupant protection and represent a safe choice. However, thanks to its more recent testing date and a more comprehensive range of modern assistants included in the standard equipment, the Audi A6 appears somewhat more complex and modern in terms of active accident prevention.

In addition to standard equipment, each model offers several unique features and technological solutions that can be decisive for the customer. Both premium brands approach added value in their own way – while one focuses on an immersive digital environment, the other prioritizes uncompromising ergonomics and innovations that facilitate everyday driving.

Audi A6: A Digital Oasis and Technological Avant-Garde

• Infotainment and Control: The MMI touch response concept in the Audi A6 (C8 generation) almost entirely eliminates traditional physical buttons. It replaces them with a pair of stacked touchscreens that offer haptic and acoustic feedback. Combined with the fully digital Audi virtual cockpit instrument cluster, the driver gets an exceptionally clean, technologically impressive, and highly customizable workspace.
• Lighting Technology: The top-tier HD Matrix LED headlights, which can be supplemented with laser high beams, are among the absolute best. Not only do they perfectly mask oncoming vehicles without dazzling them, but they also perform striking dynamic light animations when unlocking and locking the car, which have become an iconic signature of the brand.
• Chassis and Handling: For maximum agility in the city and stability on the highway, Audi offers dynamic all-wheel steering (the rear wheels turn opposite to the front ones at lower speeds). The intelligent quattro with ultra technology all-wheel drive proactively disconnects the rear axle when traction is not needed, significantly saving fuel in normal operation.
• Comfort and Smart Solutions: For absolute silence on the highway, the car can be equipped with optional acoustic window glazing. Music connoisseurs also swear by the premium Bang & Olufsen 3D Advanced audio system, which impresses with retractable acoustic lenses located directly in the dashboard.
• Sport Equipment and Variants: The popular S line package gives the car a sharper visual character and great sport seats with excellent lateral support. Models across the range use mild-hybrid technology for smoother start-stop system operation, while the top-tier S6 or RS6 series will satisfy even the most demanding drivers looking for extreme performance.

BMW 5 Series: Driver-Oriented and Intelligent Assistance

• Connectivity and Ergonomics: The legendary BMW iDrive system (version 7.0 in post-facelift models) relies on a physical rotary controller on the center console. This is invaluable for blind operation and precise selection while driving. Alternatives include the top-notch BMW Intelligent Personal Assistant voice control or visually attractive gesture control, where a simple wave of the hand in front of the screen can, for example, lower the volume or accept a call.
• Assistance Systems: A complete unique feature in this class is the Reversing Assistant. At speeds up to 35 km/h, the car continuously remembers the last 50 meters driven and can automatically reverse back along exactly the same path. This is an extremely useful function for tight garages, narrow driveways, or confusing dead-end streets.
• Technological Innovations: BMW offers the Digital Key function, which allows you to unlock, lock, and start the car using NFC technology in a smartphone. This digital key can also be easily shared remotely with family members or colleagues. Keeping the car in top condition is ensured by regular over-the-air (OTA - Remote Software Upgrades) software updates.
• Chassis and Driving Dynamics: The xDrive all-wheel-drive system is intentionally tuned to maintain the car's typical rear-wheel-drive character. Together with the adaptive M suspension and Integral Active Steering, the "5 Series" can brilliantly mask its actual dimensions in corners and offer immediate driving pleasure.
• Sport Packages: Models equipped with the legendary M Sport package are characterized not only by more aggressive bumpers and a stiffer suspension but primarily by a steering wheel with a thicker rim, which many automotive journalists and drivers consider the most ergonomically pleasant on the market. Brutally powerful M550i versions with a V8 engine or the icon itself, the M5, are also available.

The Audi A6 is an ideal choice for drivers looking for maximum comfort, technological sophistication, and understated yet precise luxury. It is a perfect long-distance highway cruiser that prioritizes quietness, safety, and top-tier interior quality over dynamic corner-carving on backroads.

The BMW 5 Series will primarily appeal to those motorists who, even in a large executive sedan or estate, demand true driving pleasure, precise chassis response, and communicative steering. Thanks to the unrivaled ergonomics of the onboard system and the harmony between the engine and transmission, it is an exceptionally versatile and driver-satisfying car.

Based on our experience from used car inspections, long-term user experience, service reports, and breakdown statistics, we have compiled an overview of the most common problems that buyers of roughly four-year-old used cars from these two premium series should watch out for.

With the current generation Audi A6 (C8), owners most often face software issues and, with selected engines, several specific hardware problems.

• Mild-hybrid system (MHEV): A very well-known and expensive problem, especially with six-cylinder engines (e.g., 50 TDI), is the failure of the 48V starter-generator (alternator). The fault often leads to rapid battery discharge and complete immobilization of the car. Audi addressed this problem in many cases under warranty, but for older used cars, it is necessary to pay close attention to it.
• Engine and gearbox: Three-liter diesel six-cylinders are criticized for significant turbo lag ("turbo hole") combined with slower automatic transmission response when starting off. Over the years, software updates have partially improved the situation. With S tronic dual-clutch transmissions in four-cylinder versions, jerking at low speeds may occur, which often indicates the need for an oil change or a control unit update. Shifting smoothness should always be verified by a detailed physical inspection of the used car.
• Electronics and infotainment: Users quite often report MMI system freezes, touchscreens going black, or wireless phone mirroring dropouts. Occasionally, assistance systems (e.g., adaptive cruise control radar) also act up, requiring recalibration due to dirt or minor impacts.
• Chassis: Models equipped with optional air suspension may start to suffer from air bag leaks or compressor wear at higher mileages, which manifests as the car "sagging" after standing for a long time.

The BMW 5 Series (generation G30/G31) is considered one of the most reliable models in its class even after years, yet it is not immune to some chronic faults that you should know about before buying.

• EGR cooler: By far the most common and well-known problem with diesel engines (two-liter and three-liter) is a leaking exhaust gas recirculation (EGR) cooler. Coolant leaking into the intake can, in extreme cases, cause the car to catch fire. Several widespread recalls have taken place for this part, so it is crucial to check whether the car has already undergone this replacement at an authorized service center.
• xDrive all-wheel drive: The xDrive system's transfer case is extremely sensitive to differences in tire wear. Using tires without BMW approval (without the star) or a larger difference in tread depth between the axles can lead to its wear and expensive damage, manifesting as jerking under load. The correct condition of the tires and the functionality of the drive is a point that every independent technical inspection of the car focuses on.
• Active grille slats: Electronically controlled slats in the front grille (Active Air Stream) tend to get stuck or their motors fail completely. As a result, the engine warning light comes on and, in the worst case, there is a risk of overheating if they remain in the closed position.
• Rear air suspension: On the more practical Touring variant (G31), which has rear axle air suspension as standard for maintaining ride height, leaks in the rubber bags begin to appear after roughly 100 to 150 thousand kilometers.

When buying a used car, a thorough inspection is key. Here are several specific points to focus on for these two models, as each has its own weak spots. To avoid very expensive surprises, a careful and independent physical inspection of a used car should always be carried out on your chosen vehicle.

When choosing an Audi A6:

• Mild-hybrid system (48V starter-generator): In a range of engines from these years (especially six and eight-cylinders, but also newer four-cylinders), there is a risk of premature failure of the 48V alternator.
• Gearbox response and throttle lag: The C8 generation with diesel engines (especially the 40 TDI and 50 TDI) often suffers from a noticeable delay when trying to accelerate quickly from a standstill.
• MMI infotainment stability and software: While the two large touchscreens dominate the interior and look great, their software can be troublesome.
• Wear of the heavy chassis and brakes: The Audi A6 is a robust, heavy car, and its kerb weight takes its toll on the wear of consumables.

When choosing a BMW 5 Series:

• xDrive transfer case: A crucial and very delicate component of the all-wheel-drive system in this generation.
• Plastic cooling system components and the EGR system: Common pain points in the engine bay for both petrol and diesel engines.
• Air conditioning evaporator (Odour from the ventilation): A quiet ailment of both pre-facelift and newer G30 models.
• Battery and smoothness in Plug-in hybrids (e.g., 530e): Hybrid 5 Series were exceptionally popular across Europe as company cars to obtain tax benefits.

Sources: ADAC, e15.cz, idnes.cz, autoexpress.cz, autoweb.cz, ceskyautoblog.cz

This article was prepared using artificial intelligence tools. The section guarantor is Petr Dušek.