Robuta

https://www.ornl.gov/content/final-report-intermediate-ethanol-blends-research-published
final reportethanol blendsresearch publishedintermediate
https://www.sciencedaily.com/releases/2013/12/131213161158.htm
Blending more ethanol into fuel to cut air pollution carries a hidden risk that toxic or explosive gases may leach into buildings, according to researchers.
ethanol blendscarryhiddenrisksciencedaily