As the previous definition mentions, it is a measurement of stench created by Adam Carolla and Dr. Drew a few years ago on Loveline.
The scale ranges from 1-100. As as benchmark, 50 hobopower is strong enough to make a person vomit. 100 hobopower is only a theoretical concept is not actually attainable (just like absolute zero temperature).
Cousin Sal cut a savage fart and everyone in the van threw up, it was probably a good 55-60 hobopower.