Audi A6 (2004)

Estimated running costs and MOT pass rates from 2,156 MOT tests in 2024.

Annual Cost

£2,227

£186/month

MOT Pass Rate

75%

Average

Road Tax

£275

Estimated/year

Est. Insurance

Grp 18-32

1871cc Diesel

Check Carefully

75% pass rate, £2,227/year to run. 7 points below average.

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Diesel1871cc22 years old2,156 tests155k miles avg

Annual Running Costs

Fuel (Diesel, 1871cc)

~48 mpg

£1,397

Road Tax

Estimated CO2 band

£275

MOT Test

£55

Predicted Repairs

£500

Total per year£2,227

Per month£186/mo

Per week£43/wk

Estimates based on 7,400 miles/year (UK average), diesel at 199.33p a litre (GOV.UK weekly average, week of 19 October 2026), GOV.UK road tax rates and repair likelihood from MOT data. Insurance not included.

Reliability Verdict

75% MOT pass rate(Average)

0%All-model avg: 82%100%

Average reliability. Expect some repairs as it ages. That's 7 points below the average of 82% across all models in our data. It falls below the Audi brand average of 90%.

75% of MOT tests on Audi A6s from 2004 ended in a pass in 2024, when they were about 20 years old. That's based on 2,156 tests across the UK, retests included. The average mileage recorded at those tests was 155,383 miles.

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How Does It Compare?

Rank among 2004 models191st of 470(top half)

Rank among Audi models1013th of 1,066(bottom 6%)

vs average of all models-7%(82% avg)

vs 2004 models average+3%(72% avg)

vs Audi average-15%(90% avg)

Mileage Analysis

155,383

Average miles

148,000

Expected for age

The average 2004 Audi A6 had 155,383 miles on the clock at its 2024 MOT, which is in line with the expected 148,000 miles for a 20-year-old car, suggesting normal everyday use.

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Best Year to Buy?

Of the years with at least 100 tests, the 2020 model has the highest MOT pass rate at 94%, while the 1997 model has the lowest at 71%. The 2004 scores 75%. Newer cars usually pass more often simply because they are younger, so compare years of a similar age.

Audi A6 by Year

Year	Pass Rate	Tests	Avg Mileage
2021	93%	2,105	36,146 mi
2020	94%	3,470	42,761 mi
2019	92%	16,657	54,594 mi
2018	92%	16,546	62,634 mi
2017	91%	19,296	75,408 mi
2016	89%	26,437	85,249 mi
2015	89%	22,966	96,950 mi
2014	88%	21,808	106,355 mi
2013	87%	20,882	115,551 mi
2012	86%	16,143	125,550 mi
2011	82%	13,126	135,985 mi
2010	81%	12,471	143,668 mi
2009	81%	8,341	150,654 mi
2008	80%	11,124	156,627 mi
2007	79%	10,782	162,839 mi
2006	78%	6,542	165,663 mi
2005	78%	3,534	163,283 mi
2004	75%	2,156	155,383 mi
2003	74%	1,408	153,657 mi
2002	73%	771	164,916 mi
2001	78%	356	157,216 mi
2000	75%	389	150,802 mi
1999	73%	410	157,368 mi
1998	76%	222	151,701 mi
1997	71%	215	176,094 mi
1996	78%	316	189,126 mi
1995	76%	136	162,842 mi
1994	81%	53	140,857 mi

Similar Cars to Consider

Ford Fiesta

2006 · 1399cc Diesel

£1,944/year

70%

-5%

Volkswagen Golf

2006 · 1896cc Diesel

£2,227/year

72%

-3%

Volkswagen Polo

2006 · 1400cc Diesel

£2,144/year

68%

-7%

Vauxhall Astra

2005 · 1598cc Diesel

£2,144/year

69%

-6%

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About the 2004 Audi A6

The 2004 Audi A6 is a premium car. Our records list a 1871cc diesel engine, though engines vary between versions. 2,156 MOT tests were recorded on this model in 2024, making it a reasonably common sight on UK roads. Among all models from 2004, the average MOT pass rate is 72%, and this model beats that benchmark.

With an average of 155,383 miles recorded at its 2024 MOT tests, Audi A6 owners drive about as much as the UK average.

2004 Audi A6 Fuel Costs

The 1871cc diesel engine offers a reasonable balance between performance and economy. Expect around 48 mpg in mixed driving, which works out to roughly £1,397 per year with diesel at 199.33p per litre (GOV.UK weekly average, week of 19 October 2026; based on 7,400 miles per year). Diesel cars of this age should have their DPF (diesel particulate filter) checked, as replacements can be costly.

What does it cost to own a 2004 Audi A6?

Total estimated annual running cost is £2,227 (£186/month), broken down as £1,397 fuel, £275 road tax, £55 MOT, and £500 predicted repairs. Repair costs are moderate, reflecting the 75% pass rate. Keeping on top of servicing will help avoid surprises.

Audi A6 Reliability Trend

Newer Audi A6s pass their MOT more often than older ones, by 12 percentage points on average, which is mostly down to age and wear.

Buying a Used 2004 Audi A6

At 22 years old, the Audi A6 is firmly in budget territory. Purchase prices are low, but check for rust, worn suspension bushes, and electrical gremlins. A full service history is especially valuable at this age. If you're flexible on year, the 2020 model has the highest pass rate at 94%.

Common Issues to Watch For

These are typical issues for cars of this age, fuel type and engine size, not faults recorded on this model's MOT tests. Use them as a checklist when you view one.

DPF (Diesel Particulate Filter)

Watch out

Short journeys clog the DPF. Replacement costs £1,000-£2,500. Check the DPF warning light and ask about driving patterns.

Turbo Wear

Watch out

Diesel turbos work harder and wear faster. Listen for whining noises and check for oil leaks around the turbo housing.

EGR Valve

Watch out

Exhaust Gas Recirculation valves clog with carbon deposits, causing rough running and poor economy. Cleaning costs £150-£300, replacement £300-£600.

Rust and Corrosion

Watch out

At 10+ years, check wheel arches, sills, subframe, and brake lines for rust. Structural corrosion is an MOT failure. Prevention is far cheaper than repair.

Suspension Bushings

Watch out

Rubber suspension bushes harden and crack with age, causing knocking noises and vague handling. A full refresh costs £300-£800 depending on the car.

Clutch Wear

Watch out

With an average of 155k miles, clutch replacement may be due (typical lifespan 60,000-100,000 miles). Budget £400-£800 for a new clutch kit.

Brake Discs and Pads

Medium risk

High-mileage cars often need brake disc replacement, not just pads. A full set of discs and pads costs £200-£500 per axle.

Engine Mounts

Medium risk

Worn engine mounts cause excessive vibration and movement. Replacement costs £150-£400 per mount. Check for vibration at idle with the bonnet open.

Service History

Low risk

Always request a full service history. Regular servicing is the single best indicator of how well a car has been maintained, regardless of mileage.

Running Costs Compared

How the 2004 Audi A6 stacks up against similar cars for estimated annual running costs, insurance group, and tax.

Car	Pass Rate	Fuel/yr	Tax/yr	Est. Ins. Group	Total/yr
Audi A6(2004)	75%	£1,397	£275	Grp 18-32	£2,227
Ford Fiesta(2006)	70%	£1,219	£170	Grp 8-20	£1,944-£283
Volkswagen Golf(2006)	72%	£1,397	£275	Grp 18-32	£2,227same
Volkswagen Polo(2006)	68%	£1,219	£170	Grp 8-20	£2,144-£83
Vauxhall Astra(2005)	69%	£1,219	£170	Grp 12-25	£2,144-£83

Estimates based on 7,400 miles/year, GOV.UK average pump prices for the week of 19 October 2026, GOV.UK road tax rates and MOT data. Insurance groups are our rough estimate from engine size, not official groups. Actual costs vary by driver, location, and usage.

Questions about the 2004 Audi A6

Is the 2004 Audi A6 reliable?

Average reliability. Expect some repairs as it ages. 75% of MOT tests on 2004 Audi A6s ended in a pass, from 2,156 tests (DVSA MOT data for tests in 2024, retests included). That's 7 points below the average of 82% across all models in the same data.

How much does a 2004 Audi A6 cost to run?

Our estimate is £2,227 a year (£186 a month): £1,397 fuel, £275 road tax, £55 MOT and £500 predicted repairs, based on 7,400 miles a year. Insurance is not included.

What is the MOT pass rate for a 2004 Audi A6?

75% of 2,156 MOT tests on the 2004 Audi A6 ended in a pass (DVSA MOT data for tests in 2024, retests included). That ranks it 191st of 470 models first registered in 2004 (top half).

Which year Audi A6 has the best MOT pass rate?

Of the years with at least 100 tests, the 2020 Audi A6 has the highest MOT pass rate at 94% and the 1997 the lowest at 71%. Newer cars usually pass more often simply because they are younger and have done fewer miles.

What is the average mileage for a 2004 Audi A6?

The average mileage recorded at MOT tests on the 2004 Audi A6 is 155,383 miles, which is in line with the expected 148,000 miles for a 20-year-old car, suggesting normal everyday use.