Reliability histories

How are cars holding up? The reliability history charts, included in each model's profile, give you the most comprehensive reliability information available to consumers. (To find our Ratings & reliability information go to our main Autos page and select a vehicle by make and model). These charts are based on 1.3 million responses to our 2010 Annual Auto Survey conducted by the Consumer Reports National Research Center. Consumer Reports subscribers reported on any serious problems they had with their vehicles during the past 12 months that they considered serious because of cost, failure, safety, or downtime, in any of the trouble spots included in the table below.

The scores in the charts are based on the percentage of respondents who reported problems in each of the 17 trouble spots. Because high-mileage cars tend to encounter more problems than low-mileage cars, problem rates are standardized to minimize differences due to mileage. The 2010 models were generally less than six months old at the time of the survey, with an average of about 3,000 miles.

To check on the reliability history of a particular year's model, start with the Used Car Verdict. This score shows whether the model had more or fewer problems overall than the average model of that year, calculated from the total number of problems reported by subscribers in all trouble spots. Because problems with the engine major, cooling system, transmission, and drive system can be serious and expensive to repair, our calculations give extra weight to problems in those areas.

To see how the model that's currently on sale is likely to hold up, look at the New Car Prediction at the bottom of each chart. For this rating, we averaged a model's Used Car Verdict for the newest three years, provided the vehicle did not change significantly in that time and hasn't been redesigned for 2011. We have found that several model years' data are a better predictor than the single most recent model year. One or two years' data may be used if the model was redesigned in 2010 or 2009, or if there were insufficient data for more years. Sometimes we include a prediction for a model that is new or has been redesigned, provided its reliability history or the manufacturer's track record has been consistently above average.

To see a model's individual strengths and weaknesses, look at the individual scores for each of the 17 Trouble Spots. The "Average Problem Rates" chart below shows the average problem rates for all models in the survey in each trouble spot. Scores are based on the percentage of survey respondents who reported problems for that trouble spot, compared with the average model of that year.

Models that score a  are not necessarily unreliable, but have a higher rate of problems than the average model. Similarly, models that score  are not necessarily problem-free, but had relatively few problems compared with other models.

Because problem rates in some trouble spots are very low, we do not assign a  or a  unless the model's problem rate exceeds 3 percent. If a problem rate is below 2 or 1 percent it will be assigned a  or a  respectively. In the charts, a model year in red identifies the year of a major redesign.

Engine, major: Engine rebuild or replacement, cylinder head, head gasket, turbo or supercharger, timing chain or timing belt.

Engine, minor: Oil leaks, accessory belts, engine mounts, engine knock or ping.

Engine, cooling: Radiator, cooling fan, antifreeze leaks, water pump, thermostat, overheating.

Transmission, major: Transmission rebuild or replacement, torque converter, premature clutch replacement.

Transmission, minor: Gear selector or linkage, coolers and lines, rough shifting, slipping transmission, leaks, transmission computer, transmission sensor or solenoid, clutch adjustment, hydraulics (clutch master or slave cylinder).

Drive system: Driveshaft or axle, CV joint, wheel bearing(s), differential, transfer case, 4WD/AWD components, driveline vibration, electrical failure.

Fuel system: Check engine light, sensors (includes O2 or oxygen sensor), emission control devices (includes EGR), engine computer, fuel cap, fuel gauge/sender, fuel injection system, fuel pump, fuel tank, fuel leaks, stalling or hesitation.

Electrical: Alternator, starter, hybrid battery and related systems, regular battery, battery cables, engine harness, coil, ignition switch, electronic ignition, distributor or rotor failure, spark plugs and wires failure.

Climate system: Blower (fan) motor, A/C compressor, condenser, evaporator, heater system, automatic climate control, refrigerant leakage, electrical failure.

Suspension: Shocks or struts, ball joints, tie rods, wheel bearings, alignment, steering linkage (includes rack and pinion) power steering, wheel balance, springs or torsion bars, bushings, electronic or air suspension.

Brakes: Premature wear, pulsation or vibration, squeaking, master cylinder, calipers, antilock system (ABS), parking brake, brake failure.

Exhaust: Muffler, pipes, catalytic converter, exhaust manifold, leaks.

Paint/trim: Paint (fading, chalking, cracking, or peeling), loose exterior trim or moldings, rust.

Body integrity: Squeaks or rattles, seals and/or weather-stripping, air or water leaks, loose interior trim and moldings, wind noise.

Body hardware: Windows, locks and latches, tailgate, hatch or trunk, doors or sliding doors, mirrors, seat controls, seat belts, sunroof, convertible top, glass defects.

Power equipment and accessories: Cruise control, clock, warning lights, body control module, keyless entry, wiper motor or washer, tire pressure monitor, interior or exterior lights, horn, gauges, 12V power plug, alarm or security system

Audio system: Audio systems, entertainment systems, navigation systems, backup camera/sensors, communication system.