Compared: Audi A6 C4 vs C5 vs C6
Three generations, one icon
Few model lines shaped Audi’s rise into the executive class like the A6. Born from the Audi 100, the Audi C4 A6 first carried the new name from 1994, the C5 A6 turned it into a bestseller from 1997, and the C6 A6 carried the line into the modern era from 2004. Today all three generations have matured from company cars into affordable used cars and youngtimers.
Our latest market data from June 23, 2026 shows how far apart the three A6 generations sit on price - and which way each is heading.
Price comparison: current market
| Model | Years built | Avg. price | Range | Avg. mileage | Listings |
|---|---|---|---|---|---|
| Audi C4 A6 | 1994-1997 | €9,300 | €1,500 - €29,000 | 184,821 km | 46 |
| Audi C5 A6 | 1997-2005 | €6,990 | €1,300 - €27,500 | 264,356 km | 22 |
| Audi C6 A6 | 2004-2011 | €4,974 | €1,290 - €9,850 | 271,732 km | 31 |
The picture is clear: the older the generation, the higher the price. The C4 is the priciest of the three at €9,300 on average - and the only one whose curve is clearly rising. Six months ago it sat at around €7,100. The C6 is the cheapest at €4,974, but still losing value (it was above €8,600 at the end of 2025). Mileage is telling too: the oldest C4 carries the lowest average at 184,000 km - a clear sign that mostly cared-for, low-mileage examples have survived.
The Audi C4: the climber turning classic
Built as the A6 from 1994 to 1997, the C4 is closely related to the Audi 100 - and counts as one of the most solid Audis of its era. The fully galvanised body resists rust, and the interior ages gracefully.
Strengths today:
- The only generation with clearly rising values
- Fully galvanised body, highly rust-resistant
- Characterful five-cylinder engines and the legendary S6
- Lowest average mileage of the three
Known weak points:
- Stick strictly to timing belt service on the V6 and five-cylinder
- Early-year electrics can play up
- Good examples are getting scarce and pricier
At €9,300 on average, the C4 is the investment of the three A6s - if you want a classic with upside, this is where to look.
The Audi C5: the all-rounder
Built from 1997, the C5 turned the A6 into a volume model and an autobahn icon. Its broad engine range from the 1.8T to the 4.2 V8, plus quattro all-wheel drive, the Allroad and the flagship RS6, make it the enthusiasts’ favourite.
Strengths today:
- Huge choice: from economy engine to the RS6 halo
- quattro all-wheel drive and the rugged Allroad available
- Timeless design that still looks modern today
- Growing scene, good parts supply
Known weak points:
- Highest average mileage at 264,000 km - high-miler territory
- Oil consumption on the 1.8T when maintenance is neglected
- 2.5 TDI with known camshaft and pump issues
At €6,990, the C5 sits in the middle on price. If you want character and versatility - and check condition closely - this is the broadest line-up of the three.
The Audi C6: the bargain
Built from 2004, the C6 brought the bold single-frame grille and plenty of modern technology. At €4,974 on average, it is the cheapest way into a big Audi - but also the most technically complex.
Strengths today:
- Cheapest entry into the Audi executive class
- Most modern chassis and best safety equipment
- Effortless long-distance cruiser, a lot of car for the money
- Wide choice of diesel and petrol engines
Known weak points:
- Falls in value the most of the three
- Complex electronics and optional air suspension are costly to run
- FSI petrols with timing chain and carbon build-up, sensitive multitronic
With the highest mileage and falling prices, the C6 is the classic high-miler bargain - cheap to buy, but only a good deal with a complete service history.
Which model for which buyer?
The value investor
Recommendation: Audi C4 A6
If you want an Audi with upside, choose the C4. It is the only one of the three with clearly rising values. A cared-for, full-service-history example with documented timing belt service is the smartest bet.
The enthusiast and all-rounder
Recommendation: Audi C5 A6
No one offers as much variety as the C5 - from frugal commuter to RS6. If you want character, quattro and a big community, this is the one. Watch the high mileage and insist on clean history.
The bargain hunter and high-mileage driver
Recommendation: Audi C6 A6
If you want maximum car for the money, the C6 is hard to beat. The market starts from €1,290. Here, more than with the others, complete maintenance matters most - ideally without air suspension and with a well-kept engine.
The maintenance question
For all three A6s, the purchase price is only half the story. Condition and history decide the rest.
- On the C4, the timing belt on the V6 and five-cylinder is the key check - the galvanised body rarely causes trouble.
- On the C5, history separates the wheat from the chaff - check oil consumption, and on the diesel the known weak points.
- On the C6, electronics, air suspension and engine history are the costliest items - here caution pays the most.
- A pre-purchase inspection (€150-300) is money well spent on any youngtimer.
Our verdict
The three A6 generations serve three different needs:
- Buy the C4 if you are betting on a solid classic with rising values.
- Buy the C5 if you want maximum variety, quattro and enthusiast character.
- Buy the C6 if you want the biggest car for the smallest money - and can find a complete history.
With 99 listings in our database, the choice is solid across all three. Which A6 generation is right depends less on budget than on your goal: investment, all-rounder or bargain.
One final tip: The oldest A6 here is also the priciest - and for good reason. Think long term and you pay most for the C4 today, and regret it least tomorrow.
Detailed price information and further variants can be found on our model pages: