Consumer Reports' Car Reliability FAQ

Where Is the Data From?
Consumer Reports obtains its reliability data from the Auto Surveys sent to Consumer Reports members each year. In all, we received responses on over 330,000 vehicles in our 2023 surveys, detailing 2000 to 2023 models and some early 2024s.

How Many Cars Does CR Have Information on Overall?
CR’s Auto questionnaire is one of the largest scientific surveys conducted in the U.S. Our 2023 surveys, which were sent to members of Consumer Reports magazine and CR.org, gave us feedback on members’ experiences with over 330,000 vehicles. This high number of responses allows CR to provide the most comprehensive reliability information available to consumers.

How Many Samples Does CR Have of Each Model?
A typical vehicle has about 200 to 300 samples for each model year. When we have small sample sizes for models, we may use brand history and the reliability of similar models that may share major components to determine our predictions. Since 2015, we use an online questionnaire exclusively instead of our previous mix of electronic and paper surveys from members. That change shrank our respondent pool, but the internet-only surveys allow us to ask more in-depth questions and solicit detailed comments about problems.

What Effect Does Having a Larger Sample Size for Some Vehicles Compared With Others Have on the Validity of the Reliability Data?
Given an appropriate sample, the more data you have, the more statistical confidence you have in your information. A larger sample will always give more reliable information than a smaller sample (assuming, of course, that the data are valid and collected from an appropriate source).

When we have small sample sizes on vehicles, we may use brand history and the reliability of similar models that may share major components. This gives us the ability to predict reliability of brand-new vehicles or ones that have been recently redesigned. We will publish the data only if we feel the sample size is sufficiently large and indicative of the model.

Are All Automotive Problems Included?
Respondents to our surveys are asked to identify problems they have experienced in a 12-month period in up to 20 trouble spots. We do not currently publish scores for active driver assistance systems and airbags because problem rates in these areas are low.

What Do the Trouble Areas Cover?
Our Reliability History charts cover problems in any of the 20 trouble areas. Here’s a look at what’s covered in each of those areas, listed in order of mechanical and more serious problems first:

POWERTRAIN is a composite of engine, transmission, drive system, fuel system, and exhaust for any vehicle with an internal combustion engine. It is a composite of electric motor, EV battery, EV charging, and drive system for electrified vehicles. In cases of hybrids/PHEVs, it is a composite of a combination of these.

BUILD QUALITY is a composite of electric accessories, body hardware, paint/trim, and noises/leaks.

ENGINE, MAJOR: Engine rebuild or replacement, cylinder head, head gasket, turbocharger or supercharger, timing chain or belt.

ENGINE, MINOR: Accessory belts and pulleys, engine computer, engine mounts, engine knock or ping, fuel leaks, oil leaks.

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

ELECTRIC MOTOR: Electric drive motor rebuild or replacement or malfunction

EV BATTERY: Hybrid/electric battery replacement, hybrid/electric battery malfunction, hybrid/electric battery cooling problems

EV CHARGING: Charges too slowly, charge connection problem, won’t charge at home, won’t work with public chargers, won’t fully charge, charging port problem, won’t DC fast charge (Note: Charging problems reported by members are with the vehicle, not with home or public chargers.)

TRANSMISSION, MAJOR: Transmission rebuild or replacement, torque converter, premature clutch replacement.

TRANSMISSION, MINOR: Gear selector and linkage, transmission computer, transmission sensor or solenoid, clutch adjustment, rough shifting, slipping transmission, leaks.

DRIVE SYSTEM: Driveshaft or axle, CV joint, differential, transfer case, four-wheel-drive/all-wheel-drive components, driveline vibration, electrical failure, traction control, electronic stability control.

FUEL SYSTEM: Sensors (O₂, or oxygen, sensor), emission-control devices (includes EGR), fuel-injection system, fuel gauge/sender, fuel pump, problems filling up the tank.

ELECTRIC SYSTEM: Alternator, starter, regular battery, battery cables, engine harness, coil, ignition switch, electronic ignition, spark plugs and wires failure, auto stop/start.

CLIMATE SYSTEM: AC compressor, blower (fan) motor, condenser, evaporator, heater system, automatic climate system, electrical failure, refrigerant leakage.

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

BRAKES: Antilock system, parking brake, master cylinder, calipers, rotors, pulsation or vibration, squeaking, brake failure, premature wear, regenerative braking.

EXHAUST: Muffler, pipes, catalytic converter, exhaust manifold, heat shields, leaks.

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

NOISES/LEAKS: Squeaks, rattles, wind noises, seals and/or weather stripping, air and water leaks.

BODY HARDWARE: Windows, locks and latches, doors or sliding doors, tailgate, trunk or hatch, mirrors, seat controls (power or manual), heated or cooled seats, heated steering wheel, seat belts, sunroof, convertible top, glass defect.

ELECTRICAL 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, USB port, alarm or security system, remote engine start, headlights, automatic headlights, automatic wipers, wireless charging pad.

IN-CAR ELECTRONICS: CD player, rear entertainment system (rear screen or DVD player), radio, speakers, in-dash GPS, display screen freezes or goes blank, phone pairing (e.g., Bluetooth), voice control commands, steering wheel controls, portable music device interface (e.g., iPod/MP3 player), backup or other camera/sensors, Android Auto/Apple CarPlay, infotainment hardware replacement, software over-the-air fixes, head-up display.

Are All Problems Considered Equally Serious?
Engine major, engine cooling, transmission major, drive system, electric motor and EV battery problems are more likely to take a car out of service and to be more expensive to repair than the other problem areas. Consequently, we weight these areas more heavily in our calculations of model year overall reliability verdict. Problems such as broken trim and in-car electronics have a much smaller weight. Problems in any area can be an expense and a bother, though, so we report them all in the reliability history charts.

What Different Reliability Scores Does CR Publish?
Consumer Reports uses the data from its member surveys to compile detailed reliability histories on several hundred makes and models of cars, minivans, pickups, and sport-utility vehicles, covering the 2000 to 2023 model years and some early 2024s. For each model that we have sufficient data on, the reliability history chart shows you whether the model has had more or fewer problems than the average model of that year in each of the relevant 20 trouble spots. That information can be a big help when inspecting and purchasing a used car. The overall reliability verdict summarizes from among 20 trouble spots for each model year and compares that with the average of all vehicles in the same model year. We use these reliability scores to identify lists of reliable used cars and used cars to avoid.

For new 2024 models that are currently available, our predicted reliability rating is based on the model’s recent history, provided the model hasn’t been significantly redesigned for the current model year. Online, predicted reliability is presented in the new-car model overview and ratings comparison pages, in car type pages under Reliability and Ratings in the Vehicle Overall Ratings comparison. It is also incorporated into the reliability history charts as the new-car prediction in print publications.

We also present reliability scores in more detail in our graphs. This presentation, with bar graphs where we used to show the score as a percentage difference between each model’s overall reliability and the average reliability of all models, is scored on a scale of 0 to 100 points. We group models by vehicle type (for example, midsized cars or minivans), for ease of comparing models that are direct-market competitors.

CR-tested vehicles are ranked in order of their Consumer Reports Overall Score. The predicted reliability rating and the road-test score are major components. Crash safety, crash-avoidance technologies, and owner satisfaction are also factors. The vehicles with the highest Overall Score that met CR’s criteria in their respective categories are recommended.

Learn more about the Overall Score.

Are These Scientific Surveys?
There are generally two criteria that social scientists use to evaluate the quality of a survey: its validity and its reliability. Validity refers to whether the survey actually measures what it says it does. Reliability refers to whether the information generated by the survey could be repeated if the survey were to be conducted again.

We have strong evidence that our surveys are both valid and reliable. The questions in the surveys are designed professionally by experts in CR’s survey research department, in consultation with our automotive engineers and statisticians. Members of our survey team have advanced degrees and many years of experience in conducting all sorts of consumer surveys. The surveys use an aided response technique that leads respondents through well-defined specific items and gives each respondent the same perspective in answering the questions. The data we report tracks well with other sources of repair and reliability information available on the market. From year to year, our members’ reports of their problem experiences are fairly consistent; when there is a difference on a particular model, we can often attribute it to known issues with a particular component of a car.

Are the Surveys Based on a Representative Sample?
A sample is considered to be representative of a population if the relevant characteristics of the population are reflected in the sample. So considering the population of interest is critical in evaluating the quality of a sample. Our survey sample is drawn from the population of Consumer Reports members. While all members are invited to participate in the surveys, participation is voluntary, and there is always the possibility that those who respond are unique in some particular way. For example, members have sometimes questioned whether those who respond are those who have a complaint to make about their cars.

One reason for this is that our surveys are omnibus surveys, asking members about not only their cars but also a dozen other products, as well as major services they have used (such as insurance, cable services, cell phone plans, and airlines). Many members return surveys reporting that they had no problems at all with their cars in the previous year. This is true for all makes and models of cars. So owners with complaints about their cars are not the only ones who return the surveys.

Any survey has some sort of sampling frame that limits the people being surveyed. We choose our members as our sampling frame. On average, CR members tend to be more educated and affluent than the general population. With the growth of Consumer Reports online, a wider demographic range of individuals has been surveyed in recent years. However, our reliability questions do not ask respondents about their attitudes or opinions about the reliability of their cars, where one might expect different groups of individuals to have different perspectives. Instead, we ask for factual information about whether specifically defined problems occurred; these types of questions are less sensitive to the nature of the characteristics of the sample itself.

Further, our results track well with other sources of reliability information available on the market.

Your Survey Results Do Not Match With My Experience. Are Your Surveys Wrong?
Even in the most unreliable models, some individual car owners are lucky and experience few or no problems during the 12 months covered by the survey. For example, in one of the worst models in our recent surveys, about 60 percent of the owners reported problems in at least one trouble area over the previous 12 months; of course, this means that about 40 percent of owners reported no problems. You might be one of those lucky owners. Of course, the opposite can happen as well—even in a model that tends to be quite reliable, there is an occasional “lemon.”

Since the Average Number of Problems Is Small for Most Models, Is Consumer Reports Overemphasizing Differences That Might Not Be Important?
Beyond statistical significance, we believe these differences are also meaningful to car buyers. We think that car buyers should expect a new car to be entirely problem-free in its first months or years of service. While the difference between two ratings may be small, a pattern of several less-than-perfect trouble spots in a brand-new car should be cause for concern and does not bode well for a model’s long-term reliability. We have not seen many models in our survey that are entirely problem-free. The 2022 Toyota Camry has very few problems, with just over 1 percent of owners reporting a problem, whereas the Volvo XC60 Plug-in Hybrid has 38 percent of its owners reporting at least one problem, the highest among 2022 models. Those differences among models are important for car buyers to consider in choosing a car. We present the ratings scores for trouble spots primarily to allow consumers to compare the relative incidence of problems among models. While there are no guarantees, you can improve your odds of buying a reliable car if you choose a model that has had a lower rate of problems in the past.

Some People Maintain Their Cars Differently From Others. How Does This Affect the Ratings?
The biggest growing area of concern in late-model cars is the in-car electronics: infotainment, entertainment, phone pairing, and navigation systems. Other problem areas include the climate system (AC compressor, condenser, heater system), and power equipment (body control module, gauges, and warning lights). Maintenance does not affect those items. Problems in those areas might more likely reflect the inherent design or quality.

How Does CR Account for Mileage Differences?
Vehicles with higher mileage will most likely experience more problems than vehicles of the same age with lower mileage. We adjust our analyses to minimize differences among models due to varying mileage. Our data are mileage-standardized by dividing cars of each model into groups of high, medium, and low mileage, and employing the statistical technique of direct standardization.

How Can You Participate in a Reliability Survey?
The surveys are only open to Consumer Reports members. If you are a member but have not received an invite to participate in a survey, it is likely that we do not have your current email address on file. Members can register to participate.