2018 Volkswagen Tiguan driving

The National Highway Traffic Safety Administration has intensified its investigation into the failure of seat belts in the 2018 Volkswagen Tiguan in two routine crash tests that the agency conducted.

“During two frontal crash tests of this vehicle, the seat belt tore apart,” the agency said in a statement to CR.

The tests were conducted less than a week apart at two different locations. In the tests, the driver’s seat belt separated and frayed, completely splitting at the point where the belt is inserted into the buckle.

These crash-test results led NHTSA to open a safety-defect investigation, or Preliminary Evaluation, and now the agency is launching an Engineering Analysis (EA), the next step in the process.

EAs have declined in the past several years at NHTSA—only four were launched in 2017. The investigation could lead to a recall. There have been no complaints to NHTSA about the issue and no reports of crashes, injuries, or deaths. The 2018 Tiguan has been on sale for about a year. 

Read the complete Volkswagen Tiguan road test.

The automaker is challenging the results of NHTSA’s test, Volkswagen spokesman Michael Tolbert said in a statement to CR. “The Tiguan was designed to meet or exceed safety standards,” he said, “and has performed well in internal testing as well as other third-party tests such as the Insurance Institute for Highway Safety.” The automaker is cooperating with NHTSA in this investigation, he said.

Russ Rader, spokesman for the Insurance Institute for Highway Safety, which conducts its own crash tests and is funded by the insurance industry, said his organization did not find any problems with the Tiguan’s seat belts, noting that the SUV won top ratings in its evaluations. Rader added that “a belt failure would be an extraordinary event in a modern vehicle. Beyond lab tests, belt failures rarely happen in real-world crashes.” 

Car Safety

Volkswagen believes testing equipment may be to blame for the seat belt failure, NHTSA noted on its EA statement. The agency also had the seat belts analyzed by the National Transportation Safety Board, which concluded that they failed from force during the test pulling in opposite directions along the length of the belt and not because of cuts or abrasion.

After the NTSB testing, NHTSA’s Office of Defects Investigation upgraded its probe to determine, among other things, a root cause for the seat belt tearing. (NHTSA has secured recalls of other vehicles without identifying a root cause, including the recall of Takata airbag inflators.) The ODI said it would review vehicle and seat belt design changes for the new 2018 Tiguan platform and any effects those changes may have had on the performance of the seat belt system. 

NHTSA photos show 2018 Volkswagen Tiguan seat belt damage.
Photo: NHTSA

NHTSA has also posted a Safety Concern on its website for the 2018 Tiguan because it found that during the side-impact test, the left driver door unlatched and opened. That’s worrisome, NHTSA says, because “a door opening during a side-impact crash increases the likelihood of occupant ejection.”

Tolbert did not respond to emailed questions about NHTSA’s warning about the driver’s door opening in side-impact crashes.

This side-impact test is commonly performed on new vehicles. The Tiguan was redesigned for the 2018 model year. The test simulates an impact from a moving vehicle at 38.5 mph. Most modern vehicles perform well in this test, and the Safety Concern designation that NHTSA has applied to the Tiguan is unusual.

“When you see that warning, coupled with the rare occurrence of a seat belt tearing apart, there appears to be sufficient risk to warrant the further investigation that the agency has pledged to perform,” says Jennifer Stockburger, director of operations at CR’s Automotive Test Center in Connecticut.