How Consumer Reports Tests Cars

How Consumer Reports Tests Cars

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To really put an automobile through its paces, you have to cover a lot of ground. Good thing the Consumer Reports Auto Test Center sprawls across 327 acres in rural Connecticut, where we push the cars and trucks we test to their limits to get all of the information and insights you need to make a smart auto purchase.

The cars team tests about 60 vehicles per year, driving them a total of about 900,000 miles. We also churn through reams of reliability and satisfaction survey data collected from our subscribers to supplement the analysis, evaluations, and ratings from the track. It takes a full-time staff of almost 30, including engineers, editors, statisticians, technicians, photographers, videographers, and support staff, to keep the Auto Test Center running.

Most automotive publications evaluate cars and trucks lent to them by manufacturers. But we purchase every vehicle we test from a dealership, just like you do. (Last year we spent $2.1 million buying cars.) That way, we can maintain our independence and test cars with the trim and options people actually buy rather than the special versions that manufacturers want to showcase.

Here’s something else that sets us apart: We’re thorough. The staff at most publications spends a day to a week getting to know a car. We drive each vehicle we rate for 2,000 break-in miles over several weeks before we even start formal testing. After that, we do more than 50 tests using state-of-the-art measurement tools. Our trained staffers use a test-track facility that includes a 4,400-foot-long main straight, a 3,500-foot handling course, an accident-avoidance course, a 33-percent rock hill, and a brake-test straightaway to gauge stopping distances on dry and wet pavement. To evaluate ride comfort, we use surrounding public roads that are studded with the type of bumps and ruts that drivers encounter every day.

Because your safety is always our first priority, we evaluate headlights on moonless nights and use carlike targets to check automatic braking systems. We also use infotainment systems thoroughly and share our experience.

In addition to testing cars, we also operate an extensive child-seat program at our Auto Test Center. For our current ratings, we crash-tested 580 seats. Plus we’re the only organization that provides independent tire ratings for consumers. Each year we test about 600 tires and rate more than 150 models.

Check our guide to Consumer Reports' Ratings.

Acceleration

Acceleration tests are conducted on a smooth, flat pavement straightaway at the track. The test car is rigged with a precise GPS-based device that’s hooked to a data-logging computer and a display that’s mounted on the windshield. This equipment creates precise records of time, speed, and distance. We use it to measure sprints from 0-30 mph, 0-60 mph, and for quarter-mile runs. For trucks and heavier SUVs, we also perform acceleration tests while towing a loaded trailer. Good acceleration speaks to more than the fun factor. It's also vital for executing safe highway merges and can potentially play a role in some accident-avoidance situations.

Transmission

Transmissions play a central role in delivering engine power to the wheels, and the characteristics of the transmission can greatly affect the overall driving experience. When evaluating transmissions, our engineers look for responsiveness, how quickly and appropriately the transmission selects its gears, and how seamlessly it shifts and downshifts. They assess how in tune the transmission is with the throttle, grade, and driver's inputs. For manual transmissions, the testers evaluate the shift action (how easy it is to move the shift lever through the shifter gate), The appropriateness of gear ratios is taken into account as well. The engineers also note the clutch action, looking for appropriate effort, pedal travel, and the point where the clutch engages.

Braking

Good braking performance is a vital factor in a car’s accident avoiding capability. Our automotive engineers conduct a series of brake tests from 60 mph to a standstill on wet and dry pavement to measure stopping distances. The test car is rigged with a precision GPS-based device. We also judge brake-pedal modulation.

Ride Comfort

An overly-stiff or uncontrolled ride can really detract from the driving experience. Our engineers judge ride comfort on a 30-mile loop at predetermined speeds on a course that includes a variety of roads containing, bumps, ruts, undulations, and a typical highway section. They note whether the suspension absorbs and isolates appropriately. They determine whether the ride is stiff, choppy, tender, or floaty, and how well the car copes with pavement flaws. The engineers are attuned to adverse ride motions such as side-to-side rocking and fore-and-aft pitching. Comfort is the name of the game, as is the ability to provide a steady cruise regardless of the terrain. Cumulative experience from commuting in the cars is also factored in.

Noise

We evaluate noise, as well as measure it, while the car is driven over various pavements, including specially built concrete slabs at our track. Complementing those findings is noise evaluation conducted by our test engineers on local public roads. They make note of engine, road, and wind noise, and judge the level and quality of the noises, be they raucous or pleasant, annoying or exhilarating.

Routine Handling

Our testers judge routine handling primarily during a test we call "one-day trip," which consists of a 30-mile loop of local roads ranging from a smooth highway to secondary two-laners, and rural twists and turns. A team of trained engineers assesses how well the car deals with curvy roads. That directly translates into the car’s agility and fun-to-drive qualities. The engineers note body control such as body lean and how steady the car remains over bumpy corners. They evaluate steering response to driver input and how well the car communicates feedback, mainly through the steering. The car's turning circle is measured by technicians as this quality translates directly into ease of parking and maneuverability in tight spaces.

Emergency Handling

Crucial emergency driving tests include an avoidance maneuver and a series of at-the-limit cornering assessments around a handling course—a snaking track loop. The avoidance maneuver is a "path-following test" in which the driver pilots the car down a lane marked off by traffic cones with a quick left-right-left sequence. That simulates swerving to avoid an obstacle in the road, then returning to the original lane to avoid oncoming traffic. The car threads through the course, without throttle or brakes, at ever-higher speeds until it can't get through without hitting any cones. We use a laser-beam based device to record and monitor entry speed. When testing on-limit handling, drivers push the car to and beyond its limits of cornering capabilities to simulate entering a corner too quickly. Test engineers evaluate how controllable, secure, and forgiving the car is through the maneuver.

Controls and Displays

Engineers trained in ergonomics/human-factors evaluate a car's controls and displays, judging how easy it is to interact with the various vehicle functions such as audio, climate, phone, and all the switches and instruments. Every auto-test staff member logs comments drawn from months of living with the cars and driving them every day for commuting, trips, and errands. The more intuitive and user-friendly the controls are, the better.

Driving Position, Access, and Accommodations

Staff members of different size, age, and gender judge how easy it is to get comfortably situated behind the steering wheel, gauging whether they can see out well and reach all controls and pedals without straining or developing premature fatigue. They also get in and out of every seat, and note the ease of entry and exit. Seat comfort is judged on comfort, support, and room.

Fit and Finish

Experienced engineers evaluate every test vehicle's interior qualities. They want to see that the trim pieces have minimal gaps and properly align with one another and that the texture of adjacent panels matches. The testers also judge the tactile quality of the plastics, leather, fabrics, and switchgear—the parts that owners interact with on a daily basis. They look for quality in sewn seams and for ill-trimmed plastic mold flash, rough edges, and hard, hollow plastic surfaces. They also pay attention to the way nooks and cubbies are finished inside and out, whether cup holders are sturdy, flimsy, or ill-placed, and whether compartment doors open and shut smoothly.

Fuel Economy

We perform our own fuel-economy tests, independent of the government's often-quoted EPA figures and the manufacturers' claims. Using a precise fuel-flow measuring device spliced into the fuel line, we run two separate circuits. One is on a public highway at a steady 65 mph. That course is run in both directions to counteract any terrain and wind effects. A second is a simulated urban/suburban-driving test done at our track. It consists of predetermined acceleration, and deceleration rates, as well as idle time. Consumer Reports' overall fuel-economy numbers are derived from those fuel consumption tests.

Headlights

Have you ever wondered whether your car's headlights are as good as they should be? To answer that question, Consumer Reports evaluates headlight performance on new cars in our test program. After aligning the headlamps in an indoor lab, we test them outdoors at our track on dark, moonless nights. Our headlight specialists set up a series of black targets at prescribed intervals along almost a thousand feet of level roadway. They then look for low-beam and high-beam performance, evaluating reach, intensity, width, and the evenness of the light pattern. They note glare effects—where stray light can bounce back from mist, rain, or fog. And they determine whether the transition or cutoff of light is so sharp that it reduces the headlight's range as it moves over undulations and uneven roads.

Safety Features

We don’t perform crash tests. We quote the government and Insurance Institute for Highway Safety crash test results. Other aspects require a personal touch to evaluate. Our engineers asses safety belts, the most important safety device, in all seating positions, gauging how easy they are to reach and adjust, how they drape on different-sized occupants, and whether they incorporate features such as pretensioners that make them more effective. The engineers also check head restraints in all seats to ensure that they are tall enough and can be positioned properly to mitigate whiplash injuries. Another key check is to judge how conducive the vehicle is to the securing of child seats of various sizes.

Trunk and Cargo Space

For cars with an enclosed trunk, we measure its usable volume with a set of typical-sized suitcases and duffel bags. For SUVs, wagons and minivans we use an expandable rectangular pipe-frame "box." We enlarge it enough to just fit through the rear opening and extend into the cargo bay as far as possible without preventing the hatch from closing. Cargo capacity is the volume enclosed by that box. For pickup trucks, we measure the volume of the load bed up to the top of the side rails.

Off-Road Capability

We check off-road capabilities for vehicles made for or advertised for off-road use. SUVs or pickups with a traditional four-wheel-drive system that includes low-range gearing or some equivalent are put to the test on varying terrain. We evaluate the vehicle's 4WD system and the driver's ability to modulate the throttle—something vital for climbing over tricky obstacles. We also judge ground clearance, axle articulation, and, of course, traction.



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