[quote=SDEngineer]
Not exactly x2. p=mv. A smaller car, being lighter, has much less momentum than a larger, heavier car, which means the collision energy with a stationary object is much lower, hence, they don’t need to absorb as much energy to provide driver protection in a collision. It doesn’t completely offset, but it’s not as cut and dried as you make it seem here.

It’s when you get into collisions with two moving objects that relative mass really puts the small car at a disadvantage. [/quote]
I totally agree. Hitting a stationary object vs a moving object yield very different result. The question then is, what are more common? Hitting another moving vehicle or hitting a wall? I would pick the former.