No worries guys. Octane rating does not change. Here in Belgium we use these fuels for years. There has always been some ethanol in fuels, they just never labeled it that way. Over here the best thing we got 98 octane with a E5 rating for our oldtimers and 2 strokes. The only thing you need to take in mind is to have ethanol proof fuel lines. Most lines available on the market now are. I just replace all mine with E85 proof ones. Never had any issues even when running E10.
C
crosserke
@crosserke