With the world’s first public crash test involving two fully electric vehicles, Mercedes-Benz is going above and beyond not only the legal requirements but also those of the ratings industry. Euro NCAP stipulates a frontal impact test using a 1,400 kg trolley with an aluminium honeycomb barrier replicating the front of another vehicle. In accordance with the specifications, the test vehicle and the trolley collide with an overlap and at a speed of 50 km/h. Mercedes-Benz, however, used two real vehicles, an EQA and an EQS SUV, which are significantly heavier at around 2.2 and three tonnes respectively. In addition, both models were faster, each going 56 km/h, which meant that the overall crash energy was considerably higher than required by law. The vehicles’ extensive deformation following the collision may seem alarming to the non-expert. For the Mercedes-Benz engineers, however, it shows that the vehicles were able to effectively absorb the energy of the collision by deforming. As a result, the passenger safety cell of both electric models remained intact and the doors could still be opened. In an emergency, this would make it possible for occupants to exit the vehicle on their own or for first responders and rescue personnel to reach them. The high-voltage system in the EQA and the EQS SUV switched off automatically during the collision.
Real-Life Crash Test: Mercedes EQA vs. Mercedes EQS SUV
Twenty-five years ago, Mercedes conducted a crash test between the Smart and a Mercedes S-Class to show that the small two-seater offered sufficient protection in the event of a crash with a larger car.
After 25 years, Mercedes has organized a new crash test between the smallest and largest electric SUV in the range at its test center in Sindelfingen: Mercedes EQA versus Mercedes EQS SUV, or in other words, David versus Goliath. Let’s see what happened.
First of all, the test was conducted under tougher conditions than the EURO NCAP. The cars were driving towards each other at a speed of 56 kph compared to 50 kph at EURO NCAP, and collided half their width (the procedure is called crash test off-set), as usually happens in accidents on national roads when a car wants to overtake and collides head-on only part of the car’s width with the oncoming car. Thus, the cumulative impact speed was 112 kph, a very high speed.
It is the first time Mercedes has conducted a crash test with two electric cars. The aim was to prove that the electric car is just as safe as a combustion engine car. In addition, Mercedes wanted to prove that a smaller electric car is just as safe as a larger electric car. There is a weight difference of 765 kg between the Mercedes EQA and the Mercedes EQS SUV. Mercedes EQA weighs 2,040 kg, and the EQS SUV 2,805 kg in the base versions.
Professor Paul Dick, Director of Vehicle Safety, said: “We conducted this test to demonstrate that there is no difference between electric and ICE cars in the event of an impact”.
In the new test center in Sindelfingen, which opened in 2016 and covers an area of 8000 sqm (90 x 90 meters), three impact tests are carried out daily and almost 900 in the course of a year. Today, however, thanks to high-performance computers, 80% of the tests are simulated, and only 20% are performed for real.
But this is the first time a crash test has been carried out between two electric models. The Mercedes EQA and EQS SUV start towards each other at 56 kph. The impact is followed by a loud bang but no fire is started.
After impact, the two cars spin, and as expected, the Mercedes EQA has a higher rebound because it is the lighter car. The fire brigade comes to assess the situation. There is only a smell from the leaking fluids from the cooling system and the airbags that have been deployed.
Julia Hinners, passive safety engineer, said: “The front end is severely affected, but this is part of the project theme. The front end is deforming badly to absorb energy from the impact and reduce inertial forces on the passengers”.
Paul Dick says they are very pleased with the test results. “We need to protect the passengers and the battery. The passenger cell and High Voltage Battery remained stable, and the high voltage system automatically shut down as it should. The risk of passengers suffering fatal injuries is very low. I am very satisfied. Our vision is to have zero fatalities by 2050”.
In the EQA, however, the front end and windscreen were significantly more damaged than in the EQS SUV. Inside, there are small pieces of glass. It is important, however, that there are no large pieces of glass detached from the windscreen which could injure passengers.
On board of each SUV were two dummies: three female dummies and one male. Measurements from 150 sensors were analyzed and showed a low risk of injury. This means that the predefined crumple zones and seat belt systems provided very good protection for passengers. Airbags and seatbelt pre-tensioning worked flawlessly. The crash test results are confirmed by computer simulations.
After the crash test, Mercedes engineers will evaluate in detail all the results received from the impact sensors, a task that will take two weeks.
