An 18 Wheeler fully loaded weighs 80,000 pounds unless it has a special permit to carry more weight than that. A Honda Accord weighs 3480 pounds. So the 18 wheeler is 22.98 times heavier than the most popular car on the road.
By contrast, the average NFL running back weighs 215 pounds. If the opposing defensive player were an 18 wheeler, then he would weigh 4940 pounds. Obviously, if opposing players could weight that much and reach the same top speeds as the running backs, then the running back would never get up after hitting their 5000 pound opponent.
When you are driving something even smaller than a Toyota Camry, then those contrasts in weight are even greater. So clearly, the 18 wheeler is going to come out relatively unscathed in the collision while the car is mangled and destroyed. Be careful out there. Your car has little chance of protecting you.