I would agree that a MH crash test (depending on the MH) would be worse than a truck in a lot of cases. A large DP might fare better than say an entry level. A class C might fare better than a class A. But even with a truck probably being on a safer side, you still have 7-15k# trailer pushing you from behind. It's also subjected to wind and wag which could flip you over in a swerve. So, it depends. I doubt there is a lot of research on the topic since crash tests aren't mandated on rv's. Most of us just don't crash. :)