There is easily purchased and very inexpensive testing kits available to determine ethanol % in gasoline. Briggs and Stratton lawn care machinery company has one for $5cdn.
Since the nation ban on E%0 fuel here in Canada, there has been much confusion among both the motorcycle and car enthusiasts, in fact downright indignant arguments at car and bike shows. The previous Gold Standard of fuels here had been Chevron 94 AKI (anti knock index), which was advertised for decades as 0% ethanol. Consistant texting has proven it is now 10% ethanol, winter and summer blend. Lack of awareness of this national ban, coupled with Canada’s winter in 98% of its land mass dictating 1-4 month storage of enthusiasts machines, has meant a booming business in shops specializing in classic machines, mainly dealing with long term storage of E5 or greater gasoline caused damage, mainly in its capacity to bond to atmospheric water as essentially one agent, which sinks to the bottom of fuel tanks, where rust takes over.
Thankfully there are weirdos like me who regularly check ethanol % values right at the pumps, and call out results on the various club social formats, many here on Facebook. In spite of being called every name under the book who call my testing results BS, it’s still something I think is important. Regarding certain jurisdictions with a certain country demanding 15% ethanol, yes it’s true. Already vehicle manufacturers like Porsche have announced cancelling sales of gasoline powered vehicles within that jurisdiction based on testing results of their cars.