The previous 5th generation Impreza and Crosstrek scored a poor rating in the institute’s updated side crash test so this is a welcome improvement.
Whenever an automaker makes a quick fix like this, I always wonder how much safer the car really is. It now gets an Acceptable rating when hit by the 37mph 4200lb sled, but how much additional headroom did the engineers leave in? Does the rating still hold up when the test parameters are changed slightly, like if the sled is going 40mph, or if it’s 500lb heavier?
I would expect that most cars are designed to get the top rating in the current crash tests, with a little extra headroom. Here are some examples of engineers planning for the future, the Mazda CX-5 scored well in both of the IIHS updated tests and its last major redesign was in 2017. The first gen Volvo XC90 performed well in the small overlap test, and it released in 2003.
I think on the contrary most cars and designed for the current tests, and not much more. Volvo is an exception to the rule, but that’s also because what differentiates Volvo is that singular focus on safety.
Case in point, almost all cars received Poor or Marginal scores when the small overlap test was introduced, and then a bunch more received Poor or Marginal scores when they started testing the passenger side. Same story for the updated side impact test, and the updated moderate overlap test.
I will try to be more specific with my phrasing, but my original reply agrees with your thoughts. Most cars are only designed to do well in current tests and only have a little extra headroom for updated tests. In the case of the updated side impact test, only the Mazda 3 retained a good rating, while the Civic, Sentra, and Corolla all dropped one level to Acceptable. In the case of new tests, such as when the IIHS first introduced the small overlap test, only a few vehicles that were designed for the scenario performed well.