I Watched the IIHS Crash Test a Mazda CX-5. Here's Why This Testing Matters

• What's new: The Insurance Institute for Highway Safety (IIHS) is a non-regulatory organization funded by the car insurance industry.
• Why it matters: The IIHS uses crash test data to make safety recommendations to car manufacturers.
• Edmunds says: The IIHS Top Safety Pick Plus award is one of the most difficult ratings to receive in the automotive industry. Seeing a Mazda CX-5 undergo a crash test, I understand why.

Once a vehicle arrives at the IIHS test facility, it undergoes all other nondestructive tests (headlights and frontal crash prevention, for example) before being readied for its date with destiny.

Preparation for crash testing includes draining the fuel tank and replacing the gasoline with a purple-dyed solvent called Stoddard, which behaves nearly identically to gasoline but has a much higher flash point, thereby presenting a much lower risk of fire or explosion during the test.

The vehicle is then outfitted with a wide array of sensors and cameras that provide high-resolution data on the forces experienced by the car and its occupants. The high-resolution part is important because, remember, a crash that happens at 40 mph lasts 0.2 seconds. The famous yellow-and-black decals and tape are also applied to the vehicle at this stage to make deformation and movement easier to see in high-speed video.

The crash-test car is kept in a temperature- and humidity-controlled room just before its date with destiny to minimize variables, and the all-important dummies are loaded in. In the moderate-overlap test, an adult-sized dummy is in the driver's seat and a child-sized dummy is in the rear. Those dummies are also festooned with sensors for data acquisition and, finally, just before the car is sent hurtling toward its fate, grease paint is applied to the dummies to see exactly where they hit interior surfaces and airbags.

The big show

With the vehicle and dummies prepared, the lights in the crash hall are turned on. These warm up for around a minute before the crash, because 750,000 watts of lights take that long to stabilize. Once the lights are ready, a button is pressed, and the vehicle is towed by cable down a 600-foot hall at 40 mph. The cable is released just before impact to ensure it doesn't affect the data, and moments later, there is a loud bang and the real work begins.

The thing that I was most unprepared for, despite having seen more than a few crashes in the wild and having been in one myself, was just how loud the impact would be. Granted, it's not like anyone typically experiences a car crash inside a building, but the impact itself and the airbags going off were enough to make me jump.

Immediately after impact, IIHS engineers swoop in to start examining the vehicle, cleaning up any spilled fluids, sweeping up all the bits of car and barrier that litter the white-painted floor and connecting to the data loggers. Camera footage from the vehicle is reviewed. In this particular instance, engineers from Mazda who flew in from Japan poked around the CX-5 to begin understanding how the vehicle fared.

The aftermath

The crash test of this CX-5 wasn't just a demonstration. The actual results from this test and others are expected to be released later this summer. While the tests are performed independently, using randomly selected vehicles to eliminate any tomfoolery by those with a financial stake in the results, the IIHS welcomes vehicle manufacturers' participation in the process. This is because the goal is to work with the manufacturer to encourage it to take the test results and continuously improve its vehicles, ultimately making the cars safer for everyone on the road.

Mazda, for its part, seems to relish the challenge of improving the safety of its vehicles, based on the ever-changing data from its own internal testing and from crashes performed by the IIHS. The moving goalposts represent a push toward the ultimate goal of zero traffic deaths, which is obviously a good thing.

Those moving goalposts also inform the nature of crash testing going forward. The tests themselves are not static. New tests are added and outdated tests are removed from the program. For example, the small-overlap test was added in 2011 and precipitated a huge jump in occupant safety when engineers began to understand that the wheel and wheelwell could intrude into the passenger safety cell in these crashes. 

Conversely, when the federal government updated its rollover protection requirements for passenger vehicles from 1.5 times the vehicle's curb weight to 3.5 times the curb weight, the IIHS discontinued its roof strength tests. It became unnecessary, so it could redirect those resources to other, more critical tests.

Here's what I learned

It's easy to forget what can happen in the blink of an eye. As a car enthusiast, I'm as guilty as anybody of bemoaning the way in which cars have become heavier and more complicated in the last couple of decades. But seeing what that added weight and cost buys you in even a relatively low-speed crash, I'd take that deal without complaint. You should too.