Octane rating has nothing to do with the E10 debate mate. Octane rating denotes an ability to resist Knock (detonation) Hi Power cars usually run a high octane rating to prevent detonation and its usually the last transition from road to race fuel. The big Issue with E10 is its corrosive properties. 95 RON E10 and non E10 95 RON have the same Octane rating. Octane rating isn't the issue, from what I can see it will effect classic cars that sit for months on end rather than daily drivers.