Electric vehicle manufacturer Tesla has once again demonstrated its commitment to engineering the safest cars on our roads. After rigorous testing, the National Highway Traffic Safety Administration (NHTSA) has awarded the 2017 Tesla Model X a 5-star safety rating in every category and sub-category — the first clean sweep by any SUV, electric or not.
“In the event of a serious crash, Model X occupants have an overall 93% probability of walking away without a serious injury,” Tesla stated on their blog. Model X is actually only second to Tesla’s Model S sedan in terms of safety, according to NHTSA tests.
NHTSA Crash Testing — How Tesla Model X Aced the Tests
A majority of crashes on America’s roads involve impacts to a vehicle’s front or side, and also vehicle rollover. Hence, the NHTSA conducts tests to replicate these scenarios as accurately as possible, rating a vehicle based on its performance. The tests conducted are:
1. Frontal Crash Test
This test simulates a head-on collision with another vehicle of similar weight. To do this, the test vehicle is propelled at 35 mph into a fixed barrier (see video above). Crash test dummies imitate an average-sized adult male driver and a small-sized adult female front passenger. Any injury to the head, neck, chest and legs is measured. Frontal crash results should only be compared between vehicles in the same weight class (± 250 lbs).
The Model X’s outstanding frontal crash results (Figure 1) can be attributed to its large front trunk (frunk), which is located where an internal combustion engine normally resides (Figure 2). The front of the Model X is able to dissipate an enormous amount of energy as it crumples in the event of a crash. This reduces the impact speed of the occupants in the vehicle, hence mitigating injury.
2a. Side Barrier Crash Test
The side barrier crash test replicates a vehicle being impacted from the side (T-boned) by another vehicle. This could occur at an intersection if either driver fails to give way. During the test, a 3,015 lbs barrier moving at 38.5 mph is slammed into the driver’s side of the stationary vehicle (see video above). It simulates an average-sized adult male driver and small-sized adult female sitting behind them. In this instance, injury to head, chest, abdomen and pelvis is evaluated. Side barrier crash results can be compared between all vehicles, no matter their weight class. Model X safety ratings for the side barrier crash test are shown in Figure 3 below.
2b. Side Pole Crash Test
Imagine driving on a wet road, rounding a bend too fast and losing control. If you are unlucky, you could hit a utility pole or a tree. The side pole crash test replicates this scenario, and is considered one of the most difficult tests to pass. During the test, a vehicle is propelled at 20 mph into a 25 cm diameter pole, which strikes near the driver (see video above). This test simulates a small-sized adult female driver, and evaluates injury to the head, chest, lower spine, abdomen and pelvis. Once again, it is possible to compare these test results with all other vehicles.
The battery support structure incorporated into the Tesla Model X (Figure 2) provides an immense amount of side impact protection. It is able to absorb energy from the impact and transfer load to the rest of the vehicle, allowing Model X to achieve its 5-star safety ratings (Figure 3).
3. Rollover Resistance Test
Say you’re driving on the highway and round a bend too fast. If you lose control and slide off the road, what are the chances of your vehicle flipping over? Accidents such as these have the potential to be the most dangerous. This scenario is simulated by driving at 55 mph, yanking the steering wheel hard, and seeing if the vehicle flips over.
Further, the vehicle’s Static Stability Factor (SSF) is measured in the laboratory. It determines the vehicle’s center of gravity — in other words, how “top-heavy” it is. The Model X, like every other Tesla, has a very low center of gravity, since the heavy battery pack is mounted below the floor pan of the vehicle (Figure 2).
Both of these measurements allow the NHTSA to calculate the vehicle’s rollover resistance (Figure 4).
“The rigid, fortified battery pack that powers Model X is mounted beneath the floor of the vehicle creating a center of gravity so low that Model X has the lowest rollover probability of any SUV on the road. No other SUV has ever come close to meeting and exceeding this rollover requirement,” Tesla stated.
Tesla Model X is indeed an incredibly capable and safe SUV. Can Tesla Model 3 — scheduled for production in July — also achieve a 5-star safety rating across the board?
Source: Tesla Blog, NHTSA.