Air Dam- Needed?

[szyg6h]

I am moderatly offroading with my 09 Yukon. The air dam is going to get broken
The manual says you can remove it for off roading, but that it should be replaced as soon as possible. I've seen many around with no air dam.
Just how important is it?

 

[bowtiefreak]

unless it acts as a scopp for cooling, I doubt it is a big deal

 

[gpracer1]

Broke mine off the 93 years ago and never replaced it...no issues.