2013's most reliable cars

If you want to buy a car that won't let you down, a new Which? survey finds Japanese-made models are the most reliable overall.

The latest Which? Car Survey has revealed the most reliable cars of 2013.

This year over 47,500 Which? members were surveyed and just under 58,000 vehicles were put under the microscope to find the most dependable cars across eight car classes.

The categories encompassed superminis, MPVs and 4x4s as well as medium, large, luxury, estate, and sports cars.

Japanese makes were voted top in six out of eight car classes for cars up to three years old as well as for those over the average three-year warranty-hill.

Calculating reliability

Which? worked out the reliability score for each car maker by looking at the number of breakdowns and faults suffered by all models in the past 12 months.

The more serious the fault and the longer it kept a car off the road, the bigger weighting it was given.

The scores for each area were then combined to provide an overall reliability score for each manufacturer.

Lastly the results were split into cars up to three years old and those over the three-year warranty period and ordered from most reliable to least in each sector.

The most reliable car of 2013

The 2005 Peuguot 107 topped the Which? dependability chart this year, with the petrol version of the supermini chalking up an almost faultless score of 99% - the best out of all eight classes for cars up to three years old.

The 107 cost an owner just £4 on average in annual repair bills and had no breakdowns reported.

For cars over the average three-year warranty honeymoon Japanese supermini the Toyota iQ scored a respectable 97.2% for reliability.

The 2008 petrol range cost just £1 on average in repair costs.

The make scored badly last year because of recalls but this year it has topped the charts.

Top in each class

Here are the most reliable cars up to three years old that Which? found in each class.

Two out of the eight categories are topped by eco-friendly Hybrid cars.

While six of the top reliable models are Japanese: Honda, Toyota, Mazda and Nissan are all Japanese car makers.

The Toyato Avensis Tourer and the Mazda MX-5 both had a 0% breakdown rate and £0 average annual repair cost.

For comparison here are the most reliable cars over three years old that were found via the Which survey.

The most unreliable car of 2013

So, which car manufacturers should you avoid if you don’t want to spend hours on the hard shoulder and hundreds of pounds on car repairs?

Well the worst car overall was in the large car class in the form of the Peugeot 407 which scored a terrible 47.6% for reliability.

The average cost of repairing one of the 2004-2011 range was £391 according to the Which? survey and the average time off the road amounted to 2.26 days.

The 2009 Volkswagen Polo attracted a score of 76.8% - the lowest out of all the cars looked at under three years old.

The diesel model had a 12% breakdown rate which was one of the highest in the supermini class. According to Which? members the cause was exhaust and electronic control unit problems.

Worst in each class

We’ve seen the shining examples of car manufacturing so now let’s take a look at the makes and models to avoid in each class for cars up to three years old.

The most unreliable cars over three years old scored much worse as you can see in the table below.

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