The most reliable cars

Take care when using reliability data for recent models. Models available for just a few years, such as the Mazda CX-3 (launched in 2016) are likely to top our reliability index. This isn’t surprising – after all, they’re effectively new cars.

Current reliability doesn’t necessarily indicate how well, or badly, a model will age. Look where older models from the same brand sit in the index. In this case, the older Mazda3 also rides high, which suggests the CX-3 will perform well over the next few years.

Check out the brand’s overall performance. Mazda again looks good in our brand index. On the flip side, it’s unlikely a brand with a history of below-average performance will suddenly create a reliability superstar. But you never know.

Not all cars from a more reliable brand will be reliable. Our data show trends and statistically significant results from a sample of 10,520 cars. But even among the best-performing brands and models, there’ll always be examples of cars with problems.

To see which cars were rated as most reliable, become a Consumer member or login.

Cars wear out and get less reliable. It’s no surprise our data show cars that have travelled more kilometres have more serious and major faults.

Cars that have covered more than 120,000km are much more likely to have serious or major faults. However, after this point, faults don’t increase much as the kilometres continue to rack up – our data suggest if you have a reliable higher-odometer car, it pays to keep hold of it.

The most common serious fault in cars, no matter how far they’ve travelled, is engine cooling. To keep a higher-odometer car rolling, you need to be fastidious about changing the oil every six months or 10,000km, and making sure radiator coolant is topped up. Keeping your car for longer doesn’t mean you’ll necessarily spend more to maintain it. Our data show owners of vehicles that have travelled more than 180,000km, on average, don’t spend significantly more to maintain their ride than owners of 60,000-120,000km cars.

For lower-odometer cars, the most common major faults reported were with the electrical system. But as cars cover more kilometres, the suspension, steering and drive systems become significantly more troublesome. At more than 120,000km, mechanical parts, such as shocks, bearings, hoses, joints and linkages, wear out. There’s not much you can do to prevent this happening, other than keep the car serviced regularly and fix the problems before they become really serious.

Facts

• Three-quarters of cars in our data with more than 120,000km on the clock are from Japanese brands.
• Higher-kilometre cars are more likely to be used every day.
• Higher-kilometre cars are less likely to be kept undercover or in a garage.
• Owners of higher-kilometre cars are less likely to follow a strict servicing schedule (but more likely to keep their car “fairly well maintained”).

Reliability

We wanted to know about reliability problems that happened in the past year. We asked about three types of fault:

Serious faults

These could cause a breakdown, take a car out of service and be expensive to repair. They include:

• engine rebuilds or replacement
• engine cooling
• transmission rebuilds or major repairs
• drive system failures.

Major faults

These are less serious, but could still cause breakdowns and result in significant repair costs and time off the road. We included:

• engine problems
• transmission problems
• fuel system and emissions
• electrical system
• climate system
• suspension and steering
• brakes
• exhaust and paint.

Minor faults

These are less critical, but may still need repair or affect owner satisfaction. They cover:

• body integrity (noise and leaks)
• body hardware (power or manual)
• power equipment and accessories
• in-car electronics.

Cars with no serious, major or minor faults were reported as trouble-free.

Our reliability index

Our reliability index, scored from zero to 10, includes serious and major faults reported in our survey.

A score of zero is the baseline for the least reliable cars. To achieve a maximum reliability index of 10, a brand or model would need to have no serious or major faults reported. Spoiler alert: no brands or models in our survey scored a perfect 10.

Unsurprisingly, the single biggest factor affecting reliability is a car’s age. Older cars are simply less reliable.

In our survey, 47% of cars were from 2009 or earlier. However, the split of older and newer cars is different for each brand and model. Our reliability index factors this in: if a brand or model has better (or worse) reliability than you’d expect for the age of the cars in its sample, our index accounts for it.

This means brands and models with older (inherently less reliable) cars aren’t penalised unduly. For example, two-thirds of Lexus cars in our survey are pre-2010 models, yet the brand has a high reliability score in our index. In comparison, two-thirds of Holden cars reported are newer than 2010, but the brand lingers near the bottom of our index.

We only analyse makes or models that have received more than 30 samples.

Satisfaction

We asked owners how satisfied they were with their car and if they’d recommend this make and model to family and friends. Answers were rated on a 0-10 scale; we consider a rating of 8-10 as “very satisfied” or “very likely to recommend”.

We asked about satisfaction with different aspects: fuel economy, comfort, driving performance, safety features, size and practicality, interior styling and equipment and value for money.

Everyone loves a bargain

We analysed which specific attributes made owners love (or loathe) their cars. Value for money was influential – if the owner thought they’d scored a bargain, they were more likely to say they were “very satisfied” with their car overall.

Other strong indicators of satisfaction were driving performance, size and practicality and comfort.

The only attribute we asked about that didn’t have positive correlation was safety. That’s likely because we hardly think about safety features – until we really need them.