Why you would compare a minivan to a compact SUV in terms of mass? The Sienna and Odyssey both weight ~4500 lbs. That's more or the same as the Grand Highlander or Pilot, both mid-size SUVs. Compact SUVs typically weight in the 3500-4000 lb range.
It's true that full size SUVs and trucks weigh even more though.
What is the physical mechanism that would cause a vehicle hitting a more massive vehicle to be worse than the same vehicle hitting a wall at the same speed? My understanding is the impulse is greater in the wall collision. It feels like a wall is the ideal test. I know there has been talk of getting the NHTSA to test offset frontal collisions, but it would still be stationary.
Regardless, I'm sorry that happened to your family. I would fear for mine if a similar thing happened. The arms race of ever more massive vehicles is an unfortunate social dilemma problem.
> What is the physical mechanism that would cause a vehicle hitting a more massive vehicle to be worse than the same vehicle hitting a wall at the same speed?
That’s not the comparison to draw. It should be why is hitting a more massive car worse than hitting a smaller car? The answer is in the physics of the collision and momentum.
Against a solid wall the advantage belongs to neither big nor small. The collision physics is identical, bar crumple zones and vehicle deformation.
That gets into my second quip about minivans. The rear row is unsafe since there is hardly any trunk.
It's true that full size SUVs and trucks weigh even more though.
What is the physical mechanism that would cause a vehicle hitting a more massive vehicle to be worse than the same vehicle hitting a wall at the same speed? My understanding is the impulse is greater in the wall collision. It feels like a wall is the ideal test. I know there has been talk of getting the NHTSA to test offset frontal collisions, but it would still be stationary.
Regardless, I'm sorry that happened to your family. I would fear for mine if a similar thing happened. The arms race of ever more massive vehicles is an unfortunate social dilemma problem.