The most reliable cars of 2004

Every 2004 car tested in Britain in one year, ranked by how often it failed. Measured, not surveyed.

Best

#	Car	Engine	Failure rate	Tests
1	Bentley Continental	6.0 Petrol	11%	1,226
2	BMW M3	3.2 Petrol	12%	1,590
3	Mercedes-Benz SL-Class	5.0 Petrol	13%	549
4	Porsche 911	3.6 Petrol	13%	2,114
5	Honda S2000	2.0 Petrol	14%	803
6	Mercedes-Benz SL-Class	3.7 Petrol	16%	1,175
7	Porsche Boxster	3.2 Petrol	16%	1,216
8	Jaguar XK8	4.2 Petrol	17%	638
9	Porsche Cayenne	4.5 Petrol	19%	737
10	Subaru Impreza	2.0 Petrol	19%	2,150
11	Smart Roadster	0.7 Petrol	20%	1,434
12	Porsche Cayenne	3.2 Petrol	20%	616
13	BMW 3 Series	3.0 Petrol	20%	2,618
14	Lexus RX300	3.0 Petrol	21%	1,681
15	MG TF	1.8 Petrol	21%	2,687
16	Jaguar XKR	4.2 Petrol	21%	502
17	BMW Z4	2.5 Petrol	21%	1,007
18	Porsche Boxster	2.7 Petrol	21%	1,284
19	Nissan 350 Z	3.5 Petrol	22%	1,412
20	Seat Leon	1.8 Petrol	22%	821
21	BMW 3 Series	3.0 Diesel	22%	770
22	Mercedes-Benz E-Class	2.6 Petrol	22%	505
23	Peugeot Boxer	2.0 Diesel	22%	1,363
24	Jaguar XJ	3.0 Petrol	22%	1,147
25	Audi A4	4.2 Petrol	22%	503

Worst

#	Car	Engine	Failure rate	Tests
1	Daewoo Matiz	1.0 Petrol	36%	574
2	KIA Sorento	2.5 Diesel	36%	955
3	Volkswagen Beetle	1.9 Diesel	35%	1,055
4	Seat Alhambra	1.9 Diesel	34%	635
5	Jaguar X-Type	2.0 Diesel	34%	1,808
6	Volvo V40	1.8 Petrol	34%	592
7	Vauxhall Combo	1.7 Diesel	34%	3,503
8	Citroen Dispatch	1.9 Diesel	34%	628
9	Ford KA	1.3 Petrol	34%	2,410
10	Renault Clio	1.5 Diesel	34%	1,363
11	Volkswagen Beetle	1.6 Petrol	34%	2,021
12	Citroen C2	1.1 Petrol	34%	1,259
13	Vauxhall Corsa	1.2 Diesel	34%	967
14	Ford Transit Connect	1.8 Diesel	33%	6,076
15	Volkswagen Beetle	1.4 Petrol	33%	753
16	Renault Clio	1.1 Petrol	33%	8,303
17	Renault Kangoo	1.5 Diesel	33%	1,878
18	Ford Galaxy	1.9 Diesel	33%	1,369
19	Renault Trafic	1.9 Diesel	33%	3,524
20	Vauxhall Meriva	1.6 Petrol	33%	2,690
21	Vauxhall Vivaro	1.9 Diesel	33%	6,334
22	Peugeot 307	2.0 Diesel	33%	1,649
23	Renault Megane	1.6 Petrol	33%	896
24	Nissan X-Trail	2.2 Diesel	33%	2,551
25	Peugeot Expert	1.9 Diesel	33%	512

What this measures

Britain tests every car over three years old against a published standard and publishes the result. This is that record for the 2004 model year, so every car here is the same age and none is flattered by being newer.

A car driven less fails less. An expensive one often sits high for reasons that are not about how well it was built, which is why the app can rank these at the same odometer reading.