TrueDelta: Toyota Prius still the reliability champ

 The current Toyota Prius has been very reliable, but a fully redesigned
 2010 model (pictured) goes on sale soon.

Even five-year-old Toyota Priuses are needing fewer repairs than most brand new cars, according to reliability researcher TrueDelta.com. 

In its quarterly study released last week, which examined the repair histories of over 10,000 vehicles between March 2008 and March 2009, the 2008 Prius averaged five dealer trips per 100 vehicles and even 2004 models needed just 29. 

The average 2008-model car has needed about 50 trips for repairs per 100 vehicles -- a 50 percent chance of needing work within 12 months -- TrueDelta has said, and the 2009 Jaguar XF luxury sedan needed 148 trips per 100 vehicles in the last year. 

(A handful of 2008 and 2009-model cars had no problems at all reported to TrueDelta over a year, but TrueDelta will share the results of their small sample sizes -- under 25 vehicles -- with readers who have signed up to provide their own data or paid subscribers.)

These results track closely with previous quarters of TrueDelta data, which the Prius has also led and in which the XF has also done poorly. TrueDelta updates its reliability results four times per year, but each time three quarters of that data is shared with the past report.

TrueDelta does not list any 2009 Priuses in its "panel" of survey responses, but the gas-electric hybrid car has changed little since 2004.

An upcoming 2010 Prius will be available soon as a complete redesign, which may or may not continue the current version's stellar reliability. First-year designs frequently have a fair number of glitches, though TrueDelta has tracked strong reliability for several new and redesigned 2009 models, including the Honda Fit, Toyota Corolla, and Audi A4/A5/S5. 

See the five least trouble-prone and the five most trouble-prone new cars in the TrueDelta study below the article in today's slideshow. 

In comparison to the oft-cited Consumer Reports reliability survey, participants in the TrueDelta research "panel" sign up and provide the year, make, and model of their cars once, and are surveyed throughout the year. TrueDelta says this reduces the problem of people only filling out the reliability surveys when they have a complaint to report and allows for information to be fresher.

Also unlike Consumer Reports, TrueDelta provides numerical data and a listing of each problem that occurred in a surveyed vehicle.

But also unlike Consumer Reports, TrueDelta does not have data on 1.4 million cars. 45,00 cars are registered in the TrueDelta panel, allowing the organization to report reliability data on only a relative handful of cars, whereas Consumer Reports reports data on almost every year-make-model combination going back 10 years. TrueDelta also reports reliability based on smaller minimum sample size than Consumer Reports. 

TrueDelta data can neither confirm nor deny Consumer Reports data that calls the Scion xD subcompact hatchback the most reliable new vehicle, as only 21 owners responded to the TrueDelta survey. And Consumer Reports offers no data on the Jaguar XF because they conducted their most recently published survey just as the car was going on sale. 

Sign up to participate in the TrueDelta reliability survey on their web site. You'll need to spend only a few minutes per year answering e-mail surveys, and car buyers will be able to benefit from the information you provide.