the reason is that ethanol and blends are hydroscopic ( absorb water) and makes the chances of water in fuel greater and harder to detect. (pilots check for water contamination before EVERY flight)
Hope this helps.

__________________
Cheers
Nick.

Roidio 2001 Holden Rodeo 4x4 2.8L TD. 2.5" Straight through exhaust sytem, heat exchanger shower system. 2" Body Lift,
And lots of fruit, B100 for 25,000 no problems.

Elsa 1983 Mercedes-Benz W123 300D. The Fastest Merc in Oz, Loving B100 Burgers