Ballistic Ping Pong Ball vs. Tennis Ball at 450km/h!

The impact mitigation features of a modern car are tested to a speed of 40kph. Above that, you are on your own. So technically, its a matter of choice: do you want to be 60kph dead or 100kph dead?

In practice a more massive vehicle does not make you safer on the road, because your stopping distance is longer and therefore your opportunity to avoid a collision is shorter. In addition, SUV type vehicles have a high centre of gravity making them prone to roll over. In addition, the suspension of a true off road 4WD is not suitable for turning at speed.

Rolling over in an SUV is bad because the vehicle is too heavy for the driver cabin and can easily crush under its own weight. For this reason, stopping distance under different road conditions , the only relevant factor for gauging a vehicle's occupant safety. In other words, being safe on the road is about avoiding collisions, not surviving collisions.

Two car collisions are not a reliable model to gauge the relative safety of a vehicle, because most road collisions are single vehicle crashes into stationary objects.