MOT failure rates for cars and small vans have been published for the first time following a Freedom of Information (FoI) request by the BBC.
For vehicles first used in 2004, Ford Transit Connect had the highest failure rate at 30.5%, followed by the Renault Megane at 28.1% and the Ford Transit.
The Toyota Corolla had the lowest failure rate with just 11.2%.
The Vehicle and Operator Services Agency had resisted publishing the data, saying it might be misleading.
The MOT is the annual test of roadworthiness that all cars and vans must pass once they are three years old.
The data relates to MOT tests carried out in 2007 and is available on the VOSA website as a PDF document consisting of 1,200 pages.
VOSA had also argued that publication would breach the commercial confidentiality of the manufacturers.
But publication was ordered by the Information Commissioner in December, who said that disclosure of the information was in the public interest.
In order to make it more digestible, Martin Rosenbaum, the BBC's FoI specialist, who pressed for the data to be made public, has converted the data into an
.
It shows pass and failure rates for cars and vans, by make, model, year of first use, and gives the general reason for each failure, such as being due to the vehicle's body and structure, brakes, the driver's view of the road, or problems with the fuel system or exhaust
VOSA has said it will publish statistics for 2008 and 2009 later this year, and then each year in the future.
There are some clear patterns here and certainly some Japanese models seem to do very well," said Mr Rosenbaum.
"We've got Hondas, Toyotas but not just those; Ford Fiestas and VW Polos - there are a number of cars that seem to do well."
High mileage
The crucial information that was not made available is the mileage of the car, or an assessment of how well it has been looked after by the owner, both of which will have a direct bearing on a vehicle's condition and its ability to pass an MOT test.
A number of Vauxhall cars appear toward the top of the list for failures among cars that were just three years old.
"Many of the failed items highlighted in this report, such as brakes, driver's view of the road, registration plates and tyres, are directly attributable to vehicles that have covered above average mileages," said a Vauxhall spokesman.
"Since Vauxhall was one of the largest suppliers of fleet vehicles during the period surveyed (2004-2007), and fleet vehicles typically cover higher mileages than most, it comes as no surprise that some of our cars appear in this list."
'Amazing'
The publication of the MOT data was welcomed by John Glynn of Glass's Guide, the well-known industry guide to used car prices.
"It's an amazing collection of facts and figures," he said.
"But I'm not sure it portrays the correct position because of the high number of small items that can lead to an MOT failure."
Mr Glynn pointed out that many owners, particularly those of workhorse vans, typically combine their tests with an annual service.
The MOT takes place first, the service corrects any faults that are found, and the vehicle is then re-tested and passes the MOT later the same day.
"I'm quite surprised at some of the high failure rates, such as the Rover 420," he said.
Kieren Puffett, editor of Parker's Guide, agreed that the information was a good cross-reference to the reputation of cars' reliability.
"This shows the importance of MOTs picking up if cars have faults and problems. They provide a safety net to see if cars are up to the job," he said.
He said further details about the reasons for failures, and mileage levels, would prove useful.
BBC News - Ford leads in MOT failures as figures are revealed
For vehicles first used in 2004, Ford Transit Connect had the highest failure rate at 30.5%, followed by the Renault Megane at 28.1% and the Ford Transit.
The Toyota Corolla had the lowest failure rate with just 11.2%.
The Vehicle and Operator Services Agency had resisted publishing the data, saying it might be misleading.
The MOT is the annual test of roadworthiness that all cars and vans must pass once they are three years old.
The data relates to MOT tests carried out in 2007 and is available on the VOSA website as a PDF document consisting of 1,200 pages.
VOSA had also argued that publication would breach the commercial confidentiality of the manufacturers.
But publication was ordered by the Information Commissioner in December, who said that disclosure of the information was in the public interest.
In order to make it more digestible, Martin Rosenbaum, the BBC's FoI specialist, who pressed for the data to be made public, has converted the data into an
.
It shows pass and failure rates for cars and vans, by make, model, year of first use, and gives the general reason for each failure, such as being due to the vehicle's body and structure, brakes, the driver's view of the road, or problems with the fuel system or exhaust
VOSA has said it will publish statistics for 2008 and 2009 later this year, and then each year in the future.
There are some clear patterns here and certainly some Japanese models seem to do very well," said Mr Rosenbaum.
"We've got Hondas, Toyotas but not just those; Ford Fiestas and VW Polos - there are a number of cars that seem to do well."
High mileage
The crucial information that was not made available is the mileage of the car, or an assessment of how well it has been looked after by the owner, both of which will have a direct bearing on a vehicle's condition and its ability to pass an MOT test.
A number of Vauxhall cars appear toward the top of the list for failures among cars that were just three years old.
"Many of the failed items highlighted in this report, such as brakes, driver's view of the road, registration plates and tyres, are directly attributable to vehicles that have covered above average mileages," said a Vauxhall spokesman.
"Since Vauxhall was one of the largest suppliers of fleet vehicles during the period surveyed (2004-2007), and fleet vehicles typically cover higher mileages than most, it comes as no surprise that some of our cars appear in this list."
'Amazing'
The publication of the MOT data was welcomed by John Glynn of Glass's Guide, the well-known industry guide to used car prices.
"It's an amazing collection of facts and figures," he said.
"But I'm not sure it portrays the correct position because of the high number of small items that can lead to an MOT failure."
Mr Glynn pointed out that many owners, particularly those of workhorse vans, typically combine their tests with an annual service.
The MOT takes place first, the service corrects any faults that are found, and the vehicle is then re-tested and passes the MOT later the same day.
"I'm quite surprised at some of the high failure rates, such as the Rover 420," he said.
Kieren Puffett, editor of Parker's Guide, agreed that the information was a good cross-reference to the reputation of cars' reliability.
"This shows the importance of MOTs picking up if cars have faults and problems. They provide a safety net to see if cars are up to the job," he said.
He said further details about the reasons for failures, and mileage levels, would prove useful.
BBC News - Ford leads in MOT failures as figures are revealed
