Something Rather Surprising from the Early NHTSA Crash Tests...

Mercedes-Benz and Volvo. Two marques synonymous with safety, especially in the '70s and '80s. Both had their largest-volume models (the Volvo 200 Series and the Mercedes W123, a forerunner of the E-Class) put through the test within a year and a half of NHTSA starting their 35 mph full-frontal crash test.

At the time these vehicles were tested, "passing" was a HIC below 1,000 and Chest G's below 60. When the "star" rating system was introduced in 1993, it was applicable to both vehicles tested afterward and retroactively vehicles that had already been tested (the test methodology and injury measures considered did not change from 1979 to 2010). Here's a rundown of the "star" system. The "passing" threshold used from 1979 to 1993 would be in the 3 star range - therefore vehicles that "passed" would receive 4 or 5 stars, vehicles that "failed" would be 1 or 2 stars, and vehicles that either barely passed or failed would be 3 stars.

5 stars: 10% or less chance of severe injury
4 stars: 11-20% chance of severe injury
3 stars: 21-35% chance of severe injury
2 stars: 36-45% chance of severe injury
1 star: 46% or higher chance of severe injury

The average 1979 vehicle, for comparison, had a 1,256 HIC and 55 Chest G's for the driver and 1,308 HIC and 49 Chest G's for the passenger, giving a 45% and 46% severe injury risk respectively, or a borderline 1-2 star performance.

The Volvo 200 Series went first: a 1979 model 244 was tested on September 18, 1979. At first glance, the car seemed to perform well, with little obvious occupant compartment damage. But this vehicle failed - and by a wide margin. The seat belts stretched too far in the test, allowing the occupants to slam into the steering wheel and dash with tremendous force. The driver's HIC was 1,782, with 52 Chest G's; the passenger fared even worse, with an 1,889 HIC and 61 Chest G's. This means that the Volvo had a 81% severe injury risk for the driver and 87% for the passenger; fatality would be possible. This was much worse than average (even for the time), and would fall firmly in the 1 star range for both occupants. The front doors were jammed, but the rear doors were operable.

The W123 - Mercedes' designation of their 1977-1985 standard (non-S Class) model - was tested on June 20, 1980, in its 240D guise. This one still failed, with a driver HIC of 1,301 and 54 Chest G's; the passenger's HIC was 1,363, with 44 Chest G's. This gave the driver a 48% severe injury risk and the passenger a 49% severe injury risk, a high-end 1 star performance. These injury measures are mediocre for the time. 22 1980-model vehicles were tested by NHTSA; two had data failures. Of the 20 vehicles with valid data, the Benz was the 10th best performer for the driver side and the 13th best performer for the passenger side. One good point to the Benz: all four doors were operable.

Whatever made the Volvo perform poorly, likely over-stretching of the seat belts, was fixed by 1982. On February 10, 1982, a 1982 model 240 DL was put to the same crash test. This time the driver's HIC was 550 with 43 Chest G's; passenger HIC was 381 with 48 Chest G's. improved to a 12% chance of severe injury for each occupant; that passed by a large margin and would be a high-end 4 star. Later 240 models stayed in the 4 to 5 star range.