One correction it is 87, not 81 octane. Share a few fuel points. Most E fuels base gasoline is 84, 86, and 90 octane before they add the high octane ethanol. E10 will undergo phase separation and water contamination in 90 days. After the E deterioration you lose 3 octane and many small engines will not run on the regular octane fuel. Most small engine fuel systems are not assembled with truly alcohol resistant parts. Nor do older vehicles have the alcohol resistant parts. Of you have a fun older vehicle run it on E free as much as possible and never store it with ethanol in the system.
M
You are correct! Thank you for catching my error. I blame chubby fingers and a weak mind.