Audi A5 is the least reliable new car

Desirable but unreliable: The Audi A5 has come bottom of the new car pileThe UK's most reliable new car is the Honda Accord, while the stylish Audi A5 is most likely to break down, according to the 2009 Which? car survey.
Although unlikely to set pulses racing, dependable family favourite the Accord will also not get tempers flaring, as it scored a remarkable 99% in the report on hassle-free motoring.

But while the muscular Audi A5 may have won praise for its looks and handling, it is also the most likely new car to leave its proud new owner posing by the roadside, scoring just 76%.

The Which? survey rates new cars on users happiness, taking into account breakdowns, faults and even niggles, which are guaranteed to get the buyer of a new car cursing.

Japanese cars fared the best, with supermini the Honda Jazz coming second with 98% alongside the Daihatsu Sirion, also with 98%, these were followed by the Hyundai i30.

The Which? survey was not good news for those who have opted for style and speed over a less inspiring dependability, with the A5 being joined by the Jaguar XF (78%) and Alfa Romeo 159 (79%) in the four least reliable.

But the family-orientated Ford Galaxy did squeeze into the unreliability stakes before the Jaguar and the Alfa, scoring a lowly 76%.

The biggest problem with new cars identified by the survey was electrical systems, which are supposedly meant to make cars more efficient, reliable and comfortable.

Dependable: The Honda Accord

Richard Headland, of Which? Car, said: 'Owning a reliable car can make the difference between getting your summer holiday off to a flying start and sitting on the hard shoulder of the M6. You can't do better than the Honda Accord, which is one of the most reliable cars we've ever surveyed.

'Japanese cars in the main seem to run like clockwork, although there are a few exceptions to the rule. It's also encouraging to see good reliability scores for the bestselling Ford Fiesta and other small, economical cars.'

Most reliable new cars

1 Honda Accord (2008-present) - 98.5%
2 Honda Jazz (2008-present) - 98.2%
3 Daihatsu Sirion (2005-present) - 97.5%
4 Hyundai i30 (2007-present) - 96.8%
5 Ford Fiesta (2008-present) - 96.2%
6. Honda Jazz (2002-2008) - 95.9%
7 Honda Civic Hybrid (2006-present) -95.7%
8 Citroën C1 (2005-present) - 95.7%
9 Toyota Prius (2004-present) -95.0%
10 Mazda 3 (2004-2008) - 94.4%

Least reliable new cars

1 Audi A5 (2007-present) - 75.8%
2 Ford Galaxy (2006-present) - 76.3%
3 Jaguar XF (2008-present) - 78.0%
4 Alfa Romeo 159 (2006-present) - 79.0%
5 Land Rover Discovery (2004-present) - 79.5%
6 Ford S-Max (2006-present) - 79.9%
6 Land Rover Freelander (2006-present) - 80.1%
8 Volvo XC90 (2002-present) - 80.6%
9 Jaguar S-type (1999-2007) - 81.2%
10 Hyundai Santa Fe (2006-present) - 82.2%