Answer:
Minivan.
Step-by-step explanation:
The answer seems like an obvious pick for the semi truck, but it's most likely the minivan. Let's compare them like this;
Let's say a 5'10, 160 pound man tackles you. His wide-spread body is hitting you all at once. Or the semi truck comparison. The hit is spread out and it has more weight along with it.
Now, the same guy punches you in your stomach. The punch will most likely hurt more because it's more concentrated on one spot. That's the minivan comparison. The minivan, being smaller, can only concentrate on one spot of the victimized target.
The semi truck may destroy it worse than the minivan, yes, but the minivan will have more force against the object due to the one concentrated point instead of the hit being spread out along the entire target.
Sometimes, the semi truck may be a greater foe, but the minivan would apply more force in more situations.