The bars are probably more effective at pre-pulverizing road kill.

 

Just the real thin boned stuff like birds and squirrels and rabbits, anything more substantial will wipe out that rotted out from the inside piece of mild steel that looks intimidating but isn't Brush Guard.

According to most people, they only increase the degree of damage to the hood and can result in the vehicle being declared a total loss by the insurance company in event of an accident.

The cost of the hood replacement is usually higher than the value of the vehicle I have heard.

 

I guess that depends how thick the bars are. The bars on an RTE bumper would probably pulverize well

 

The stock brush bars tend to rust thru from the inside and eventually become "air-rated". You could grate cheese with mine when I took it off and scrapped it.