Here’s an AvWeb article from 12 years ago:
https://www.avweb.com/insider/flying-g100ul-yeah-it-works/
Quote:
“It’s a little heavier than avgas–6.4 pounds compared to 6.0 pounds–but it has higher energy density so it’s within a couple of percentage points of being a wash.”
There are no exotic chemicals in G100UL. The BTUs of the constituent components are well known and easily calculated.
What have you ‘seen’ that says it has the same or less energy density? I suspect the source of such an assertion would benefit from spreading FUD (Fear-Uncertainty-Doubt) about G100UL.